Parasitizing behaviour of american cockroach egg, Periplaneta americana was important process , leading to understand egg parasitized and mass rearing the Tatrastichus hagenowii. An cockroach egg and each sex egg parasitoid of one day are were put in a test tube. Each parasitization was observed out of 10 females. Findingtime average was 10.7 minutes to meet cockroach egg. It went up on the egg and drumed with antenae to find the suitible point, which was the central ridged egg with average 56 percent and survey time average was 6.8 minutes. Lay time average was 29 minutes. The total average of the process was 46.5 minutes. Two parasitized experiments were done in a normal living room of two men, the dimension, 4.80 , 6.80 and 3.80 with width , length and height respectively. Cockroach egg of 2-5 days were attached at 4 positions of 3 high levels, each position had 2 oothecal eggs. The former egg parasitoids were 240 females, 44 males and 120 females, 22 males in the later were released in the room. Parasitized time was 10 days, both experiments , percentage of parasitization were equally 16 and eggs on every height were parasitized.