The egg parasitoid (Terastichus hagenowii) is able to parasitize many species of cockroach. The experiments were done to find the methods of mass rearing the parasitoid by using american cockroach egg (Periplaneta americana) as a host for biological control of cockroaches. Most of 1-15 days host age were parsitized and there was no statistical significant between these ages. Twenty days of oothecal age were secondary parasitized. The average offspring were 59 females and 6 males per one ootheca. Age of parasitoid less than one day and 1-3 days could parasitized average an ootheca and there was no statistical diffdrence. Each ootheca had 37 females and 4 males offspring. The ratio of copulation between female and male were 1:1, 1:2, 1:3, 1:4 and 1:5 could parasitized 1-2 ootheca and there was no statistical difference. The average offspring were 58 females and 11 males per one ootheca. Only 12 percent of ootheca were parasitiazed by unmated female parasitoid. Offsprings were absolutely male, most of them could not made hole out. Therefore male offsprings of 60-129 were dead in the ootheca. Mass rearing parasitoids in a bigger container should be used, oothecal american cockroaches age 15 days and parasitoid mother age not more than 3 days.