Emergence characters of different populations Trichogramma dendrolimi and T.chilonis at different relative humidity were compared.Percentage of factitious host eggs with emergence outlet,percentage of pupae to emerge as adults and the average number of emergence holes per parasitic egg were determined.The results showed that reaction of emergence of different species and ecotypes of Trichogramma to relative humidity was different.M-TC strains of T.chilonis preferred high humidity and couldn’t abide at low humidity.S-TL strains of T.dendrolimi could resistant to high humidity and low humidity.S-AC strains of T.dendrolimi emergence well at suitable humidity.These characters can be used in different geographical and climate conditions.