Earth experienced major biological and environmental revolutions during the Precambrian-Cambrian transitional interval, in which the abundant macro-algal were found from the early metzoan biotas in Guizhou Area. The macro-algal not only plays important role in the early evolution of algae plants but also provide some available information in the research of animal evolution and environment change. By means of a longitudinal comparative study, the change trend of the L. dissolutum from Ediacaran to Cambrian was found the thallus became shorter and wider gradually with the filaments tapered off. This diversification may make the thallus adapt to the change of ecological environment from Ediacaran to Cambrian and also allows itself to be survived during the Precambrian-Cambrian transitional interval. The result indicates L. dissolutum is a kind of maroalgae which has wide ecological tolerance and relatively high degree of inherent genetic stability.