The purpose of this paper is to have some comparison with export competitiveness of high-tech products in the U.S. market among China, Japan and South Korea, explore competitive advantage of high-tech exports among those three countries in the U.S. market, draw lessons from the successful experience of Japan and South Korea, and seek breakthrough to improve the competitiveness of China’s high-tech products exports. With China, Japan and South Korea as the research object, we had some comparison with the conditions of high-tech products export among those three countries from 2004 to 2013, using used the export similarity index to make it clear in comparison of export trade structure among those three countries. After that, the shift-share analysis method is adopted to analyze and have comparison with export competitiveness of high-tech products in the U.S. market among China, Japan and South Korea in detail and drew the conclusion finally. Analyzed by the method above, we’ve got the following conclusion: China occupies the dominant position, Japan holds disadvantage position and South Korea is at a disadvantage position compared with China in the competition among those three countries, but it has a shrinking tendency on the gap between China and South Korea.