The present number, population structure and characteristics of wild boar were studied on the basis of ecological principles and methods in Ziwuling forest area of east Gansu, from September, 2002 to May, 2003. Comparing with domestic pigs, the reproductive performance, food in winter, grazing behavior, digestible nutrients, and the ability of regulating light intensity and temperature of wild boar were observed under farm domestication. Regression between footprint distance and body size and weight were analyzed. The main results are as follows:1) There were totally about 1641±138wild pigs in this area, among them 304±26 mature males, 425±36 mature females and 912±77 sub-maturing pigs are included according to the survey of population structure in the same season (namely mature 44.4%, among them mature male 18.5%, mature female 25.9%, sub-mature 55.56% , no young ).2) Wild boar reachs the sexual maturity at the age of 20-22 months old under wild conditions in Ziwuling forest area, while wild sow at 16-18 months old. Estrum of wild sow belongs to seasonality and often estrus in October to November. Wild boar estrus none seasonally and mate all the year. Pregnancy duration length is 113±3d (n=3) and is one day less than domestic sow. A litter size is averaged at 3-5 piglets under wild conditions.3) Among the 15 collected plant species, the most favorable food for wild pigs are fruits of Malus baccata,, Pyrus betulaefolia,, Crataegus pinnatifida, Rosa xanthina, and seeds of Quercus liaotungensis. In addition, the fruit of Acanthopanax senticosus and the seeds of Cornus walteri and Toxicodendron verniciflnum are more favorable.4) The average daily intake are 2.42 0.45 kg, 3.98 077 kg, and 4.34 0.51 kg respectively for wild pigs of weighing 30~50kg, 50~80kg and 80-100 kg at a medium nutrition level under wild conditions.5) There were significant difference (P <0.01) on daily intake between wild pig and domestic pig, Bamei, at the same level of live-weight (53kg), i. e. daily intake of wild pig was 29% less than Bamei. It shows that the daily amount of protein digested by Bamei was higher than that digested by wild pig, however, digestibility of protein, and the daily digested amount and digestibility of crude fibre from wild pig were higher than that from Bamei significantly (P <0.01). Except these, differences between wild pig and Bamei for other tested nutrients were not significantly (P >0.05 )6) There were no significant difference of absolute and relative weights of heart and liver, and absolute weight of lung between wild pig and Bamei, while the relative weight of lung of wild pig was higher than that of Bamei significantly (P <0.01). In exception of the length of large intestine from wild pig is less than Bamei significantly, other indexes as the capacity of stomach and large intestine, and the length of small intestine were all smaller than Bamei significantly (P<0.01).7) Results of endurance on temperature indicated that both wild and domestic pigs have different reaction of none adaptation below-13 or above 27, but wild pig has stronger endurance to high and low temperature than Bamei. It shows that the range of temperature from -13 to 27 is relatively fitting the growth and activities of wild pigs.8) Analyzing synthetically the effects of light intensity on activity frequency and intake of wild pig, Bamei and Landrace, the range of light intensity adapted to wild pig is smaller than the domestic, but the variance of light intensity has more effects on wild pig within a fitting range of light intensity. That shows that wild pig has higher sensitivity to light intensity than domestic pig, and wild piglike an environment of weaker light at 20 1x-90 1x. So, light intensity should be controlled within 50 1x to meet this habit when wild pig is tamed.9) Eight regression equations are put forward for estimating wither height, trunk length and heart girth and live-weight by given footprint distance and footprint size.10) Under the same feeding cond