The real purpose of the government science and technology input-output is to promote the economic growth and social progress at regional and national scale. It is necessary to carry out the performance evaluation on the government’s science and technology input-output. The research should start from analysis of overseas and domestic research status and take urban science and technology input-output as the research object. The research has put forward basic ideas and key indicators of constructing science and technology performance evaluation model in Beijing，which is based on government science and technology input-output performance evaluation theory research and problems existing in the practice exploration，together with concepts，goals，functions and models of government science and technology input-output.