The study of necessity entrepreneurship and opportunity entrepreneurship have been a hotspot of entrepreneurship research. This study reviews the meaning of necessity entrepreneurship and opportunity entrepreneurship, and then make a comparative analysis of necessity entrepreneurship and opportunity entrepreneurship in following aspects: the contribution of economic growth、the barriers of entrepreneurship and characteristics of entrepreneur. There are three affecting factors of necessity entrepreneurship and opportunity entrepreneurship are explored, and they are family、trait of entrepreneur and regulatory business cost. At last, this study conclude research situation of necessity entrepreneurship and opportunity entrepreneurship and bring forward the research direction.