This paper draws on the method of De Loecker and Warzynski (2012) to measure the markup of Chinese manufacturing enterprises, and studies the impact of imported intermediate inputs on firms’competitiveness by taking product differentiation degree into count , based on highly disaggregated Chinese transaction-level trade data and firm-level production data from 2000 to 2006.After controlling for the endogeneity of imported intermediate inputs, we confirm that firms can benefit from intermediate input imports; further, we find imported intermediate inputs improve more firms’markup which produce complex goods than those producing homogeneous goods. We take market concentration into account and the result reveals that the higher market concentration is conductive to strengthen the positive influence of intermediate input imports on firms’markup. However, the little impact of intermediate input imports on firms’markup in heterogeneity industry can be explained by weak import spillover effect due to low R&D efficiency. Finally, the results of quantile regression show that, compared with the firms of lower initial markup，the firms of higher markup can get more benefits from imported intermediate inputs.