The present study examined the relative effect of direct and indirect written corrective feedback (WCF) on L2 learning and the mediating role of language anxiety in the effectiveness of these two types of WCF. Forty-five Chinese L2 learners of English were randomly assigned to three experimental conditions: direct WCF (n = 15), indirect WCF (n = 15), and control (n = 15). The learners performed two text reconstruction tasks designed to elicit the past counterfactual conditional over two treatment sessions. The treatment effect was assessed by a grammaticality judgement task and a picture-cued production task before and immediately after the treatment. Language anxiety was measured by the Foreign Language Classroom Anxiety Scale. The results showed that both treatment groups performed better than the control group on the two assessment tasks, but no significant differences were found between the two treatment groups. In addition, the results suggested that the effect of indirect WCF was mediated by individual differences in language anxiety.