Leaves are the primary sites for plant photosynthesis and disease-resistance, showing great diversity in shapes. Thus, leaves are the good model for studying the morphogenesis as well as the evolution of complex organs. Simple leaves and compound leaves are two basic forms in nature. Significant progresses have been made in understanding the simple leaf development. However, several key questions for compound leaf development have not been addressed. As we know leaves initiate from the peripheral zone of the shoot apical meristem (SAM). However, how stem cells of compound leaf primordia are regulated by the coordination of genetic factors, hormones and environmental signals, and finally to control the plasticity of compound leaf shape which remains poorly understood. Recent years, more and more plant biologists focus on the molecular mechanism underlying the diversification of compound leaf shapes. Here, we discuss some key progresses in the research of compound leaf development, and point out the hot topics in the future research.