This paper introduces the diversity of magmatism in terms of the theory and suggests that the comagmatic evolution cannot represent all kinds of magmatism. As there exist some problems in the practical application of the mapping method of lithodemic units (or hierarchical system) of intrusive rocks, the authors point out that the theory of comagmatic evolution is not perfect yet. The role of the theory of comagmatic evolution should not be overstated factitiously. It is not suitable to use this method in granitoids of all ages with various tectonic settings before intensive study experiment are erformed.