With the development of science and technology and market globalization,the era of knowledge economy is coming.The intellectual capital is becoming the motive factor of business performance and value.The intellectual capital(IC) investment such as information technology(IT) investment,research and development(R&D) investment,training and development(T&D) investment by Chinese firms are increasing.Making use of questionnaire and multiple regression analysis and artificial neural network model and taking 106 firms of Chinese listed manufacturing companies as the sample,this research explored the effects of intellectual capital investment and intellectual capital on business performance,so as to enhance the managers' confidence of intellectual capital investment and reinforce the investment and its management.