self-improvement
noun [ U ] uk/ˌself.ɪmˈpruːv.mənt/ us/ˌself.ɪmˈpruːv.mənt/
自我提高
the activity of learning new things on your own that make you a more skilled or able person
In the interest of self-improvement, I took a Spanish course. 为了自我提高，我上了西班牙语课。