Effective access and mobility in cities arethe bases for achieving urban sustainable development. Today, in Asia, uncontrolled growth of cars and motorcycles has undermined human health, urban environmental quality, economic productivity and social equity. Indicators and practices indicate that efficient public and non motorizedtransport, and prudent restrictions on private motorized vehicles have been proven effective in not only reducing the negative impacts of unsustainable transport but also in providing a means to improve the basic quality of human life.Someattempts have been made to develop sustainable transport indicators, STI. A few studies actually apply STI to compare sustainability among various cities. In this paper 21 Asian cities ranked in terms of urban sustainable transport composite index and the best and worst Asian cities identified. Then, the key factors that have influencedsustainability in these cities have been extracted.The study database is created from UITP databank: “Millennium cities database for sustainable mobility” or MCDST. Firstly sustainable transportation indicators were selectedby reviewing past researches.  Some indicators are edited or redefined. Consequently, 3 indicators in each 3 groups of environmental, economical and socialwere developed. Then composite index was also suggested by combination of 9 standardized indicators. According to composite index various cities were compared. Finallysome important factors affecting urban transportation sustainability were determined by using correlation analyses between composite index and cities’ characteristics.