This study aims to analyze the effect of proactive personality and entrepreneurial leadership on innovative work behavior mediated by work engagement in state civil apparatus at the cooperative service in West Sumatera. The type of research uses explanatory research. While the research approach uses an explanatory survey that emphasizes quantitative research methods. The entire population Civil Service of the Cooperatives Department in West Sumatera totaling 664 people, with a sample size of 250 people. The sampling technique used proportionate stratified random sampling. Data analysis using Partial Least Square (SEM-PLS). The mediation testing strategy uses the path coefficient significance. The results of the study found proactive Personality has a positive and significant effect on work engagement. Proactive Personality has a positive and significant effect on Innovative Work Behavior. Work engagement has a positive and significant effect on Innovative Work Behavior. Entrepreneurial Leadership has a positive and significant effect on work engagement. Entrepreneurial Leadership has a positive and significant effect on Innovative Work Behavior. Work engagement mediates the influence of Proactive Personality and Entrepreneurial Leadership on Innovative Work Behavior with the form of mediation is complementary mediation in the form of partial mediation.