The known marker systems of red egg ( re ), white egg (w2 ＆ pe), the fourth brown egg ( b-4 ) and the normal type-black egg of silkworm Bombyx mori were crossed with 20 red egg systems of unknown genes preserved in silkworm gene bank in China, and cis-trans complementary test was conducted to identify the genes controlling their egg color and to study their inheritance. A new mutant gene, pink like egg, an allele of re, designated as re^p, was isolated from 03-310 system. Phenotypically, this mutant was found to be characterized by pink eggs and pink eyes of the moth. Six systems appeared to be homozygous for the genotype of re/re. Five systems had additional genes controlling the white egg, light red egg or orange red egg besides the genotype of re/re. Two systems were confirmed to be homozygotes of the fourth brown egg (b-4). Redbrown egg occurred in the other 6 systems and was controlled by maternal inheritance. The two egg color controlling genes b-4 and re were found to be complementary, and the homozygote (b-4/b-4 re/re), a new egg color mutant, appeared as orange egg. 13 Refs. In Chinese.