In　order　to　lead　people　to　pro-environmental　transportation　modes,　it　is　necessary　to　learn　about　the　psychology　and　behavior　of　users.　Based　on　the　extended　theory　of　planned　behavior-incorporating　habit,　descriptive　norm　and　personal　norm,　this　paper　analyzes　the　relationship　between　these　elements　and　intention　to　use　bus,　and　the　influence　of　habit　on　intention-behavior.　The　result　of　survey　conducted　in　Chengdu　City　reveals　different　outcomes　from　previous　study,　especially　for　the　attitude　and　perceived　behavior　control.　In　addition,　the　intention　to　use　bus　and　habit　can　explain　41.7　%　variance　of　the　bus　use　ratio　to　the　total　travel.　However,　the　interaction　of　habit　and　intention　is　insignificant.