This paper analyzes whether and how informatization influences the comparative advantage of a country's high-tech industries. Informatization may reduce the cost of information elements and enhance the endowment of information elements of a country. The enrichment of information elements may promote manufacturing exports in two ways: Firstly， it will directly reduce the cost of the product per unit by accelerating a firm's speed of response， saving the cost of dealing with uncertainty， strengthening the synergy of industrial chains， and reducing the trade cost related to information. This is the Factor Endowment Effect. The second is the Technological Innovation Effect. It promotes manufacturing exports indirectly through promoting technological innovation by the accumulation of related information factors， human capital and R&D capital. For the manufacturing industry， the information elements of high-tech industries are more intensive than those of the mid-tech and low-tech industries， so that the upgrading of informatization may have a greater impact on high-tech industries， which may advance the comparative advantage of a country's high-tech manufacturing industry． The panel data of 39 countries in 1995—2011 are used for the empirical analysis. The result shows that， firstly， high-tech industries are 9.28 percent point higher， and mid-tech industries are 0.91 percent point lower than low-tech industries respectively in information intensity on average. Secondly， the change of a standard deviation of informatization level has a 0.26 standard deviation's effect directly on manufacturing export， and a 0.073 standard deviation's effect on it indirectly by increasing R&D expenditure， which suggests that Factor Endowment Effect and Technological Innovation Effect both work， and the former plays a leading role. Thirdly， the impact of the two effects both decline gradually for high-tech， mid-tech and low-tech industries， which proves that informatization may strengthen the comparative advantage of high-tech industries． This paper may contribute to the existing research in the following ways: Firstly， it casts some light on the mechanisms of how informatization may affect manufacturing exports and the comparative advantage of high-tech industries. Secondly， previous researches proved the existence of the effect of informatization on exports， but this research provides experiential evidence for the existence and importance of its two mechanisms. Thirdly， to eliminate the statistical illusion from repeated calculation and the division of the world industry chains， this research used value-added trade data to calculate trade indices， which may be more exact than the previous studies which mainly used customs trade data． Language unification and the large population provide China with a huge network which developed countries do not have， endowing China with rich information resources. With a solid foundation in manufacturing， China has greater capacity to absorb information technology and greater first-mover advantage than other large developing countries in the age of information. China should make use of the wealth of information elements to accelerate the transformation and upgrading of manufacturing industries， especially high-tech industries．