This study examines whether exporters become more productive through estimating a production function using Chinese firm-level data from 1997 to 2000. The results indicate that exporters are more productive and, more importantly, that export strategies promote the productivity of these firms. The test for the relative timing of export behaviour and gains in productivity provides strong evidence for the existence of learning-by-exporting effects rather than self-selection effects. These results are robust when controlling simultaneous bias and selection bias by using a fixed-effects model, SYS-GMM estimation and semi-parametric estimation.