The purpose of this paper is to explore the effectiveness of vocabulary enhancement activities on vocabulary learning in an ESP course. In designing the activities, technical terms on journal entries were chosen for the acquisition of language necessary for the successful implementation of accounting major's professional tasks. The desirable difficulty approach and the four strands principle,focused input, meaning-focused output, language-focused learning and fluency development, were guidelines in combining subject matter and English language learning. To test the result of the activities, the Vocabulary Knowledge Scale was employed to measure students' knowledge of 50 vocabulary items. Subjects of the ESP course in discussion comprised 200 accounting juniors in Guangdong University of Foreign Studies in China. Half of them in Group A read the texts and did matching exercises and translation exercises. The other half in Group B read the texts and practiced journal entry activity, targeting at accounting concepts and terminologies. The results revealed that Group B gained better results than Group A at a post-test. After the test a reflection on the vocabulary activities was gathered among the participants of Group B. The feedback further proved that the students did benefit from the enhancement activities on selected technical terms.