From the cuticular wax of the female German cockroach, Blattella germanica (L.), two components of sex pheromone responsible for male wing-raising were isolated as crystalline forms, and characterized as 3,11-dimethyl-2-nonacosanone (Compound A, Ia) and 29-hydroxy-3,11-dimethyl-2-nonacosanone (Compound B, Ib). Compound A and B independently elicits the wing-raising behavior, and Compound B is almost 10 times more active than Compound A. Both of synthetic compounds also exhibited the identical biological activity to those of natural ones, respectively. Besides Compound A and B, a minor component of the pheromone Compound C) was detected, and was identified as 29-oxo-3,11-dimethyl-2-nonacosanone (Ic). Of two asymmetric carbon atoms in Compound A, carbon-3 was concluded to be S-configuration. Several analogues of the pheromone were synthesized in order to figure out the effect of structural modification of the pheromone on the biological activity.