Intra-industry trade of Brazil: analysis of determinants through the gravity equation This study aimed to determine the influence of characteristics for countries and industries in intra-industry trade (IIT) of Brazilian manufactured products, considering the annual trade flows for the period 2002 to 2006 and using a gravity equation adapted to analysis this form of trade. The explanatory variables are related to market size, represented by proxy LPIBij, differences between per capita incomes of countries represented by proxy LdPIBpcij, and tariffs imposed by importing countries, represented by proxy LTarifas. These variables were used to analyze the intra-industry trade and its horizontal and vertical components. The theoretical basis to make the segmentation of intra-industry in Brazil, according to such characteristics, was derived from studies conducted by Falvey (1981), Helpman and Krugman (1985) and Greenaway et al.(1995). The measurement of the Grubel-Lloyd index and the subsequent separation of components from IIT using unit value indicates that the brazilian intra-industry trade has a strong predominance of IIT-Vertical Low quality. The results of the estimation of the gravitational equations with the use of panel data and the use of Poisson Pseudo-Maximum-Likelihood proved to be the most suitable for econometric estimation. The results for intra-industry "total" indicated that the market size, has a positive effect on the flow of exports of Brazilian products with intra-industry trade (0,517), however, the differences between per capita incomes (-0,183) of countries and tariffs in importing countries (-0,356) have a negative relation. The results for vertical and horizontal intraindustry trade have the same signals than intra-industry "total" but they differ in magnitude. .