Ant Forest is a gamified service equipped in Alipay promoting alow-carbon lifestyle. Users have a personal carbon account to keep track of daily pedometers, using public transportation, utility payment and other urban activities related to low carbon life. By doing so, the records would automatically be transformed into the number of carbon emissions being reduced. Then would be converted into virtual “green energy” for users to raise a virtual tree on the app in their Ant Forest account. Users and their friends can collect energy for each other.(Social and peer influence)When energy earned reached a certain level, the team of the app would plant a real tree in a remote area in China. The Ant Forest is not only a successful prototype in behaviour changing but also very engaging and inspiring. It encourages more users to live sustainably by participating in raising a virtual tree (gamified, engaging). It enables small actions to accumulate and become a collective contribution. Users could build connections, gain a sense of accomplishment by using the app.