In the newspaper mill, with the increasing use of recycled fibers in recent years, stickies problem is becoming more and more evident. They are from waste paper and released during the repulping process, including many types of synthetical materials, such as hot melts, adhesives and coating bonders etc. They often adhere to the furniture surface as sticky deposits or remain in the paper to form spots. Meanwhile, wood resins are introduced into papermaking system when some kinds of mechanical wood pulps are used as furnish. Thus, stickies problems become more serious and some other troubles related to anionic trashare caused accordingly. Those problems need to be faced carefully and solved urgently, since they have great negative influence on the runnability of paper machine and the quality of final products. Stickies and resins are characterized by stickiness and lipophilicity, so they are called sticky contaminantshere. This paper focuses on those sticky contaminantsand their physical-chemical characteristics, deposition mechanism and chemical control. Guangzhou Paper Mill is chosen as example, which uses deinked pulp (DIP), Masson pine thermo-mechanical pulp (TMP) and groudwood pulp (GP) to manufacture newspaper. Through the analysis of sticky deposits formed in paper machine dry section, polyvinylacetate (PVAc), poly acrylate (PA) from DIP and resins and their metal soaps from TMP & GP are identified as the real chemical components leading to the deposits formation. According to the analysis results of sticky deposits, some model substances, such as PVAc, PA and tall oil of Masson pine are chosen as substitutes for those sticky contaminants. Besides, styrene-butadiene rubber (SBR) is also used as supplementary model for one common component of stickies. Chemical characterization, simulation study on colloidal dispersing properties and some general comparisons are carried out. All of them exit in the water as colloidal form in the range of particle size from 100nm to 1000nm under pH5.0~9.0. All other sticky contaminants have obvious negative charge except PVAc with almost no electric property, but the cationic demand of resins is far higher than that of PA and SBR. Additionally, different performances are shown in their conductivity and turbidity. Deposition mechanisms of sticky contaminants are investigated by use of rotating mixer. It is found that the formation of insoluble calcium soaps is a must to resin deposition, which is closely related to the deposits amount. Addition of cationic agents is an important reason for secondary stickies deposition due to charge neutralityof catching agents with low molecular weight and bridgingof flocculants with high molecular weight. Their deposition is also affected by pH value, temperature, concentration and stickiness etc. It is believed that resins and their soaps could be only deduced to deposit largely under acidic condition, PA always has strong depositing tendency in a wide pH range, but lower stickiness of SBR and PVAc results in less or no deposition. Since the rise of temperature and concentration increase their stickiness and aggregation probability respectively, more deposits are always obtained. As for the newspaper mills with more contaminants origins and higher water closure degree, more studies are focusing on the retention control of sticky contaminants. Therefore, some different sticky contaminants-pulp systems and chemical agents are chosen and their fixation adaptability and related mechanisms are researched. Generally, at the same dosage, the fixation ability of them are showed as follows sequence: PA>PAVc>SBR> Resins, due to their different cationic demand, particle size distribution and aggregation tendency. Flocculants shows not only better efficiency of sticky contaminants fixation than catching agents, but excellent retention and drainage function to fibers. For example, under experimental conditions of FP (DIP60%+TMP30%+GP10%) consistency 0.3%, model sticky contaminants dosage 6.67% (to O.D. pulp), temperature 50℃and agents dosage 2.5mg/L, retention ratio reaches 87.0% when using polyamide FL28, but that reaches 94.2% when using amphoteric polyacrylamide Am-PAM50. The effects of sticky contaminants retention on paper quality are also studied. The results show that the retention of them on paper enhances brightness and opacity to some degree, but drops the density and impairs physical strength evidently. The higher retention ratio of sticky contaminants, the more loss of the strength. Therefore, retention control is always on the basis of pulp system with a low content of sticky contaminants and there is often a contradiction between high retention ratio and good paper strength. If sticky contaminants, as a part of dissolved and colloidal substances (DCS),can be removed by dissolved air flotation (DAF) in the circulation of process water, it will become a good way to control them. Through the classification and analysis (by centrifugation and filtration) of contaminants in the process water from the newspaper mill, it is found that DCS is predominant contaminant (about 90%, w/w) in the water of DIP, TMP and GP, but colloidal substances are not more than 40%. There are many differences in particle size distribution, Zeta potential, cationic demand, conductivity, turbidity and CODcr owing to different origins of those DCS. Some researches on their flocculating possibilities are carried out by use of coagulants and flocculantaids, which are proved to be effective for DCS removal. However, the removal adaptability and efficiency of these agents are different due to different DCS physical-chemical properties. After chemical treatment to the inlet waters of DAF in the two deinking production line, CPAM FO4190 is showed to have the best effect and the DCS removal ratio reaches 15% and 5% respectively when FO4190 dosage is 10mg/L. The removal objectives are limited to those particles sized over 2500nm, in another words, the removed objectives are limited to CS with the removal ratio of 59.7% and 15.5% respectively.