This paper discusses the connotation of high precision map of automated driving in depth, analyzes its important role and compares it with conventional map in terms of expression content, data type and the freshness, then summarizes its data forms. The methods of high precision map building using vehicle-borne mobile mapping system, low-altitude photogrammetry are investigated, and the updating method based on crowdsourcing data is introduced. At last, the problems of the lack of industry standard, the limitation of map accuracy and the prohibition of online service of some map content by law is discussed.