For his whole life, Master Hsing Yun has promoted the idea of “oneness and coexistence,” hoping that people coexist harmoniously and enjoy happy life, on which and many different merit they could advance in their spiritual cultivations. The Master defines “oneness” as “equality” and “tolerance,” while “coexistence” as “loving-kindness” and “integration.” His own summary is that “‘oneness’ is the contemplation of equanimity; ‘coexistence’ is the contemplation of loving-kindness.” He also says, “Without loving-kindness everything one does is the act of Māra.” This is like what the Avatamsaka-sūtra states “practicing the roots of goodness without bodhi-citta is the act of Māra.” Hence, the Master’s idea of “oneness and coexistence” is based on a canonical doctrine. The Japanese scholar Shigeo Kamata suggests that Master Hsing Yun’s thought of Humanistic Buddhism is built on the Avatamsakasūtra. In fact, the master once said that when starting to construct the Buddha-light Mountain the design of the “World of Lotus Store” was inspired by the doctrine of a mustard seed containing a Sumeri, which evidently shows that the Master indeed based his idea of “oneness and coexistence” on some doctrines of the Avatamsaka teaching. This paper treats the question of building a humanistic pure land with the principle guidance of “coexistence.” It suggests that even though to build a pure land is not easy, [the thought] enhances the confidence of beings, bringing them happiness, hope and convenience, and setting them a goal, which all serves as a skillful means actually leading the beings from small bliss towards greater happiness and even to the happiest state. The Master promulgates Humanistic Buddhism for the ultimate purpose is to build a pure land. If the pure land is nowhere but in the human world, then so will be the Western Pure Land of Amitabha, which is to say that a pure land of “coexistence” can be realized and completed right in human world.