Learners inevitably have errors in second language learning, and in fact, if there are no errors, there will be no opportunities for learners benefiting from the error feedback. The research into corrective feedback has gained prominence in the studies of SLA. Based on Ellis, Loewen, and Erlam’s (2006) research into corrective feedback, the paper tries to investigate the relative effectiveness of implicit and explicit corrective feedback in terms of learning a new grammatical item---subjunctive mood in a college. Three questions in the following were designed for the study: (1) Is corrective feedback effective for learners in terms of learning a new grammatical structure? (2) If there is effectiveness of corrective feedback, do learners learn more from one type of corrective feedback than from another type? (3) Of the two types of corrective feedback, which one do learners prefer, implicit one or explicit one? Why? The quantitative research method was employed to check the effectiveness of implicit and explicit corrective feedback. The major findings of the study can be summarized as follows: (1) Corrective feedback is effective for learners in terms of learning a new grammatical structure. (2) Explicit corrective feedback has greater effect on learning a new grammatical structure.(3) Explicit corrective feedback receives more popularity than implicit feedback, and the main reason given by the learners is that explicit feedback increases their awareness of the rules and items of subjunctive mood.