Abstract: The development of vertical specialization and the advancement of information and communication technologies have tremendously affected labor markets around the world. Following developed economies, China has also seen wage polarization in the labor market. The paper introduces offshore undertaking into the Ricardo model of Acemoglu and Autor (2011). Through theoretical deduction, it explains the impact of offshore undertaking, routine biased technological change and technology spillover caused by offshore undertaking on the wage structure. The results are as below. (1) By increasing the productivity of high skilled labor, offshore undertaking leads to wage polarization. (2) Routine -biased technological change can lead to wage polarization, and its impact on the high- skilled groups is higher than on low skilled groups, which is consistent with the capital. skill complementarity hypothesis. ( 3) The intermediate effect of high-skill occupations, middle- and high- skill occupations and low -skill occupations is significant ，indicating that offshore undertaking has further intensified wage polarization through the technology spillover effect. Therefore, the government should pay attention to the trend of supply and demand of occupations，and organize training programs. The above-mentioned measures will not only help China fulfill the ascent on the international industrial value chain. But also help improve the wage structure of China's labor market.

Keywords: Wage Polarization, Outsourcing Undertaking, Routine Biased Technological Change, Technology Spillover