The purpose of this study was to examine the mediating effect of informal learning activity on the relationship between Leader-member exchange(LMX) and work engagement of industry-university cooperative division staff in Korean colleges. For doing so, this study used three kinds of survey questionnaires such as LMX-MDM(Liden & Maslyn, 1998), Informal Learning Questionnaire - Korean Version(Choi, 2009), and Utrecht Work Engagement Scale(Schaufeli & Bakker, 2004). Survey respondents were employees who are working at industry-university cooperative division in Korea and 367 questionnaires were used for testing hypotheses. The results of this study were as followings: industry-university cooperative division staff’s LMX, informal learning activity and work engagement showed positive correlations among one another. Industry-university cooperative division staff’s informal learning activity had mediating effect on the relationship between LMX and work engagement(partial mediation). Based upon these results, several suggestions were made to enhance informal learning activity and work engagement of employees in industry-university cooperative division in university.