Modeling and Simulation (M&S) High Level Architecture (HLA) has become the IEEE standards. Focusing on system modeling and simulation based on HLA,this dissertation has studied the following both from theory and practice:firstly to analyze and discuss HLA Federation (that is a distributed simulation system) Development and Execution Process (FEDEP) including Persistent Federation and Multi-Federation with details to specify the essence of HLA and provide guidelines for development of large scale simulation system based on HLA,then focusing on the characteristic of HLA to study the issue of model in HLA federation development,federation design ,federates development,federation testing and federation security.The goal of model studying is to identify all the models,their roles and relations between them. These models can classify into three categories:conceptual models,HLA object models and implement models. If there were Conceptual Model of Mission Space (CMMS),the conceptual model of federation (FCM) can be easily developed by extracting knowledge from CMMS in term of federation scenario. FCM is the precondition for federation design and federation development. Based on the FCM to select federates and allocate their functionalities,develop the HLA object models (including simulation object mode (SOM) and federation object model (FOM) and translate them into the implement of federates is the essence of issue of model in HLA federation development:this will affect not only on if the federation goals can be achieved,but also on if federates can be reused later. So this dissertation not only describes the roles of conceptual models,HLA object models and implement models of federates,the relations and differences between them,but also discusses how to develop and describe them with tools.The simulation system complied with HLA is distributed and consists of not only one federate. While designing a federation,the following must be considered carefully:How many federates consist of the federation? What functionalities each federate will be responsible for? Is each federate implemented by modifying the legacy simulation or developing new one? Is each federate a virtual simulation,constructive simulation or live simulation? How to transfer the object attribute ownership between federates? This dissertation studies above typical issues while designing a HLA federation with some examples.A federate can be implemented by modifying a legacy simulation or to develop new one,but all the relations between models must embodied by the implement of federates. This dissertation studies how to develop a federate under this two situations,provides the developing tools,and gives some examples.This dissertation also studies how to test a federate,how to test a federation with multiply levels. Finally,this dissertation reviews the federation security and the next works need to do.In Practice,this dissertation has creatively finished the following works:to derive and expand the theory and method for simulation development based on HLA;to develop the object model developing tool KD-OMDT that is complied with DMSO HLA OMT specification and will be updated to comply with IEEE 1516.2 soon;to design and guide to implement the object model library (OML) shared by internet net;to modify a large scale flight analysis and training system with HLA;to use the CASE tool Rational Rose to develop HLA simulation system;to design and guide to implement a automatic tool used to develop HLA simulation with Matlab/Simulink.