[Purpose/significance] Government data openness must rely on powerful legal guarantee. American government data openness legislation takes the world lead. It’s successful experiences have active reference meanings for Chinese relevant legislation work. [Method/process] Using document consultation, comparison and comprehensive analysis methods，the paper reviews domestic and abroad research on government data openness at present, leads to research item. Also, the paper describes the situation of American government data openness and untangles its relevant legislation evolution, gives a key analysis of American“New Act Benchmarking”: US the Open, Public, Electronic, and Neces? sary (OPEN) Government Data Act’s main contents and characters, realistic meanings. And contrasts the situation of Chinese and American government data openness legislation, analyzes the advantages and Chinese reference applicability of American government data openness legislation. Based on these, the mentalities of legal regulation of Chinese government data openness are put forward. [Result/conclusion] We should explore the mentalities of legal regulation of Chinese government data openness from four aspects: specifically takes“Citizen’s Public Data Right”as the right ba? sis of government data openness; to draw up Chinese Government Data Openness Law based on Regulations on disclo? sure of government information and Data Security Law of P.R.C. ; to coordinate the balance of government data openness and personal information protection; to make clear the certification license and legal authorization.