According to basic input-output tables of China in 1997(124 Departments),in 2002(122 Departments) and in 2007(135 Departments),this paper firstly compares and analyzes growth trends of total output of information industry and other industries,then analyzes the industrial relevance of information department with other departments,and analyzes response coefficient and influence coefficient of each industry,each major industry and information industry internaluty by multiplier effect theory.Research results show that China's present economic growth mainly results from computer manufacturing industry,electronics and communication equipment manufacturing industry,mechanical manufacturing industry and so on,which is similar to foreign development trends.Thus,governments should continue to make active information industry development policy for boosting sustainable,healthy and rapid development of China's eonomy.