Lao Tzu has no monograph on the concept of time, but Lao Tzus philosophy includes his view on the Time, called Lao Tzus Philosophy of Time. Lao Tzus concept of time is the most prominent characteristics of concept of cycle time. This paper discusses the basic connotation and ideological origin of Lao Tzus concept of time, his thought of “ens” and “zero” and the Daoism that expresses the essence of this concept, and Lao Tzus study on the evolution of morality that shows his view on the development process of thing. These studies will help us to understand Lao Tzus scientific concept of time as well as the modern concept of time.