It has been widely argued that willingness to communicate (WTC) in a second language (L2) is a dual construct of the learner's trait and state. This study aimed to explore the relationships between trait-level antecedents (students' demographic features) and their L2 WTC. A sample of 1502 university students was recruited to participate in this study. Data of their age, gender, family socioeconomic status (SES) were collected. A questionnaire of L2 WTC was adopted to measure the participants' WTC in meaning-focused activities and WTC in form-focused activities. A path model was tested via structural equation modeling and significant relationships between student demographic features (age, gender and SES) and L2 WTC were observed. The major findings were: (1) male students had higher WTC in meaning-focused activities, but female students showed higher WTC in form-focused activities; (2) student age was negatively related to WTC in meaning-focused activities; and (3) students SES positively predicted WTC in meaning-focused activities. Implications for L2 instruction in tertiary education were also discussed.