Abstract：In order to broaden the germplasm resources of purple Chinese cabbage，create parent material of dark purple Chinese cabbage，and study the genetic law of dark purple character，this experiment took the selfing and backcross descendant of dark purple leaf colors from F1 crossing the dark purple Chinese cabbage germplasm‘15NG28’with green Chinese cabbage as material；observed the chromosome numbers of dark purple Chinese cabbage；investigated the leaf colors of each progeny and separation ratio；crossed dark pure Chinese cabbage with cytoplasmic male sterile CMS96 to transfer CMS lines．Results showed that 22 Chromosome numbers of dark purple Chinese cabbage material could be obtained from selfing 4th generation．After selfing，the dark purple character in leaf blades would not separate again，meaning homozygous dark purple material was obtained．It was speculated that its genotype was 20A + 2B，as monosomic alien addition lines of 20A genome subjoin 2B genome．Further research discovered that the inheritance of dark purple characteristic is dark purple Chinese cabbage was not in accordance with the classical Mendel law．It was mainly displayed the separation ratio of dark purple leaf color plant with green color plant from separation progeny was random occurrence．Only F1 hybrid from crossing homozygous parents，progeny from selfing homozygous parents of dark purple color could show stable dark green color．
