Abstract: The rock-painting of Helan Mountain is a unified language system with connected concepts and visual images. There are three types of symbols in the language system: resemblance, imagery and abstract symbols. Resemblance symbol refers to symbols with a clear specific denotation and simulation; imagery symbol refers to symbols containing the performance relationship among symbol; abstract symbol refers to symbols indicating the alleged object in human spirit. Many resemblance symbols in the rock-painting of Helan Mountain show that human had a more comprehensive understanding to the outside world and their relations, and that the application of three symbols broke through the limitations of the pictographic rock-painting and enhanced its expressive competence.