In order to measure technology innovation ability of China and compare it with other countries,we propose an evaluating method of national technology innovation ability based on BP neural network in this paper.First,it sets up an index system to national technology index using indicators in "European Innovation Scoreboard"(EIS),and then designs the BP neural network model according to the index system,and presents the feasible evaluating procedure.The computing result shows that the Technology Innovation Index(TII) of China is far behind the developed countries of the world.It ranks 22nd among the 33 countries compared by EIS and only stronger than most Eastern European countries.