Introducing　private　capital　into　the　public　transport　system　for　its　sustainable　development　has　been　increasing　around　the　world.　However,　previous　research　ignores　emissions　and　energy　consumption　impacts,　which　are　important　for　private　capital　investment　policy-making.　To　address　this　problem,　the　system　dynamic　(SD)　approach　was　used　to　quantitatively　analyze　the　cumulative　effects　of　different　private　capital　investment　models　in　public　transport　from　the　environmental　perspective.　The　SD　model　validity　was　verified　in　the　case　study　of　Jinan　public　traffic.　Simulation　results　show　that　the　fuel　consumption　and　emission　reductions　are　obvious　when　the　private　capital　considering　passenger　value　invests　in　public　transport　compared　with　the　no　private　capital　investment　and　traditional　investment　models.　There　are　obvious　cumulative　reductions　for　fuel　consumption,　CO2,　CO,　SO2,　and　PM10　emissions　for　100　months　compared　with　no　private　capital　investment.　This　research　verifies　the　superiority　of　the　passenger　value　investment　model　in　public　transport　from　the　environmental　point　of　view,　and　supplies　a　theoretical　tool　for　administrators　to　evaluate　the　private　capital　investment　effects　systematically.