Some biotic and abiotic factors affecting the biology of the pred­atory mite, Typhlodromus athiasae P. & S. were studied using immatures of Tetranychus urticae Koch as prey. Relative humidity 70%-85% were the optimum as shortened life cycle (8.4 and 9.1 days) and increased fe­male fecundity (14.5 and 12.9 eggs/female/10 days) at 25°C. Single mated female gave the shortest longevity (40.5 days) and the smallest fecundity (12.8 eggs/female), while full companionship with male allover longevity (multiple mated) gave the longest longevity (48.6 days) and the greatest fecundity (46.3 eggs / female). T.urticae gave the greatest attractancy percentage (40%) (adults, 15%; immatures, 15%; eggs, 10%) in the shortest time (6.5, 8.5, 11.3 minutes, respectively) for fed predator female. Also, fed female was better than 24 hours starved and the latter better than 48 hours starved female. Low temperatures of 5 and 10°C increased egg incubation period as cold storage preceded. To­tal hatchability percentage decreased with increase of cold storage from one to four weeks with less percentage at 5°C (61% to 10%). Females proved to be better stored than eggs. Thin smooth reticulated plant leaves (Bauhinia) resulted in acceleration of development (7.8 days) and increase egg deposition (16.8 eggs/female/10 days) than coarse reticu­lated leaves (guava) (9.7 days and 10.7 eggs/female/10 days).