In the process of second or foreign language acquisition, the learner's mother tongue or dominant language directly or indirectly affects the acquisition of the target language, and plays a positive or negative role in promoting or interfering respectively. This paper adopts an analytic and a descriptive approaches in analyzing the positive and negative language transfers of Nigerian students' Chinese language essay writing in the Department of Chinese Studies, Nnamdi Azikiwe University, from four aspects: grammar, syntax, vocabulary, and mechanical accuracy. This paper puts forward recommendations for learners and teachers on the use of effective teaching and learning strategies to reduce the negative language transfer.