In courtship behavior, the male house fly first orients towards the female, then jumps, and lands on her dorsum. After landing, some males fly away from the female after a few seconds whereas some males move backward to make genital contact. In the latter case, if the f3male is not receptive, the male also flies away after a few attempts to make genital contact. In observations of mating behavior of the house fly, Musca domestica, we found that the male shows a precise preference for the female house fly. Therefore, in the laboratory, we paired 5-day-old male house flies with females selected from one of four age groups (1-, 3-, 5-, and 7-days-old) yielding four experimental groups. The male house fly displayed clear preferences and different mating periods against different aged females. The males generally preferred to mate with virgin, larger, and more sexually mature females. In particular, most male house flies preferred to mate with 7-day-old virgin females. However, there were no significant differences in the number of eggs laid by the female aged from 5 to 10 days after emergence. The duration of each mating episode was also different. A mount and composition were also different in number of days after emergence.