Abstract: Reviewed in the present paper are four most important factors stimulating the development of molecular systematics: improvement of molecular biological methods, complete sequencing of genome, recognition of evolution rules of increasing number of genes widely used in molecular systematics, and study of fossil DNA. Systematic importance of both nuclear genes and chloroplast genes is discussed. In addition, some exciting results in molecularphylogeny constructed from sequence analyses of rbcL, matK, 18s rDNA and ITS are enumerated respectively. Moreover, the authors put forward some problems needing attention in molecular systematic study.

Key words: Molecular systematics, Review