The effect of constant temperature and relative humidity on the development and reproduction of the tomato russet mite (TRM), Aculops lycopersici (Massee) was investigated. The results showed that the survival rate of TRM were highly effected by rearing temperature and relative humidity, the highest was 89.9% at 23℃ (53%RH) and 87.1% at 75.5%RH (26℃). The developmental duration of TRM decreased as rearing temperature increased from 14℃ to 35℃, and increased as relative humidity increased from 30% to 100%. The developmental zero of egg nymph and from egg to adult of TRM were 10.51℃， 9.02℃， and 9.15℃, respectively. A total of 105.56 degree-days above a developmental zero of 9.15℃ were required to complete development from egg to adult emergence. The obvious effect of temperature and humidity on the reproductive rate of TRM was observed. It was found that the duration of oviposition decreased with increasing temperature and increased with increasing humidity. Fecundity was highest at 26℃ (53%RH) and 53%RH (26℃) with 44.3 eggs and 42.2 eggs laid per female, respectively. The highest intrinsic rate of natural increase was observed at 26℃ (53%RH) and 53%RH (26℃) as 0.2645 and 0.2669, respectively. The results showed that the optimal temperature interval for its development should be within 26-29℃ and the optimal humidity interval be within 53%-75%RH.