The Variation of morphological characters in different locations at the same time and also on the different months at same location were caused the formation of honeybee races and the evolution of honeybees during the period of time.In order to study the effect of time and season on the morphological characters of honeybee (Apis mellifera L.) ,twelve morphological characters of bees were measured from 20 colonies monthly from february till october , in Karaj ,Iian . The resulsts obtainad showed that the months at year had a significant effect on the variation of nine characters including forewing length ,forwing width , cubital index, A4 Angle ,proboscis lengh . scutellum colour , Hindleg lengh ,lengh of tergit 3 + tergit 4 , sixh stcrnit in(lex. thirth tergit colour.
)