The present paper describes the multiple sex-chromosomes found in Otocryptops sexspinosus, a species of Chilopoda. It was found that the present species possesses a 4X-5Y mechanism of the sex-chromosomes in the male. They show the chain-like association at the first metaphase. The formula of the chromosomes is 6A+X1-X2-X3-X4+Y1-Y2-Y3-Y4-Y5 in the male, and 6A+2X1-2X2-2X3-2X4 in the female.
