Climate change could profoundly affect the status of agricultural insect pests. This study is a predict of the two-spotted spider mite in potato and tomato cops annual generation peaks under current and expected future climate by using the relationship between the accumulated thermal heat units expressed as degree-days unit (DDU) and the population fluctuations. The results indicate the population of the predicate annual generation number and duration of T. urticae of tomato and potato crop under current and expected future climatic changes and their relationship with accumulated thermal units (degree-days units), at Beheira, Bani sweif and Sohag governorates. Under current climate mean generation numbers of T. urticae (10-12 and 12) and mean numbers days per generate (21-19 and 19) and mean degree-days units for T. urticae (170.7- 170.9 and 167.4) at Beheira, Bani sweif and Sohag governorates, respectively were highly recorded compared with expected future climate in 2050s and 2100s. Meanwhile, future predicate in 2050s and 2100s, mean generation numbers (15-17 generation) were highly recorded, but mean degree-days units (165.2-172.3 unit) were highly recorded and days numbers per generate (14-17 days per generate) were less recorded compared with data of current climate, respectively.