The author uses the stochastic frontier production function to measure the relationship between the level of openness and technical efficiency in China. First, the Chinese average technical efficiency was steadily increasing since 1990. Second, the gap of technical efficiency among the regions was becoming more and more larger, and the main power of improving technical efficiency comes from the East Region since 1990. Thirdly, the openness had playing a important positive role in improving Chinese technical efficiency, moreover, the foreign direct investment' contribution was much more than international trade in promoting technical efficiency.