This study examines the lexical ability of hearing impaired university students. A total of 100 university students participated in this study and they were divided into as a control group and an experimental group. The data were collected by the questionnaire including their background information and the measurement of their lexical ability and were analyzed by the use of the SAS 8.2 statistical program. The study’s findings are as follows: (a) the lexical ability of the hearing impaired students is far less than the one of the control group, especially on the level of middle and high school lexis; (b) the relationship between the lexical ability of the hearing impaired students and their background information regarding their hearing impaired age and their impairing level was found to be somewhat correlated; and (c) more importantly, the hearing impaired students’ difficulty about learning English is different from the one of the control group and they were less exposed to learn English from the beginning. The discussion presented in this paper can lead to a better understanding of the reality of the hearing impaired students’ lexical ability, which can help develop, adapt and disseminate sound and practical information concerning the English lexical ability of hearing impaired students.