We develop a model that enhances our understanding of how different supports for development motivate employees to pursue self-development. After collecting data from 418 employees with different backgrounds and using structural equation modeling and bootstrap analysis, we found that work support and nonwork support for development made unique contributions to employee self-development. The relationship between non-work support for development and employee self- development is mediated by self-efficacy and career motivation. The relationship between work support for development and employee self-development is mediated by career motivation. This research expands the support for development from work environment to a broader social environment and clarifies how both work and nonwork supportive environment is positively related to employee self- development. Finally, we discussed practical implications for personnel selection and career development in organizations