This paper constructs an industry-level time sensitivity indicator, by combining the data on the share of air transportation at the product-export level and input-output table. Then it investigates the impacts of transportation infrastructure on export trade from the perspective of time sensitivity, by using enterprise data of China's industrial sector from 1998 to 2007. The empirical results show that:firstly, the "time sensitivity" varies substantially with industries, and a more innovative high-tech industry has much higher-level time sensitivity; secondly, the quality of transportation infrastructure has obvious effects on export trade; the express and first-class highway which are of higher quality than other roads play a more significant role in enterprise export participation and the amount of exports; thirdly, regarding the impact channels, both respective-province and neighboring-province transportation infrastructures promote enterprise exports and have more significant effects on industries with high time sensitivity, while respective-province transportation infrastructure plays a bigger promotion role; fourthly, foreign-owned enterprises, compared with domestic enterprises, are more sensitive to transportation infrastructure, showing that transportation infrastructure is actually an important factor affecting foreign capital inducement. Therefore, the improvement of transportation infrastructure is beneficial to the transformation of comparative advantages in China's export into high-tech industries, thereby promoting the transformation and upgrading of export structure.