Abstract: This paper deals with the basic biology of woolly apple aphid Eriosoma lanigerum (Hausm.)for the effective control of this pest.The base development temperature was 13.42℃ for the first instar,9.45℃ for the second instar,6.57℃ for the third instar,5.34℃ for the fourth instar respectively.Effective thermal summation of the whole generation was 186.98 day-degree.Maximum mean fecundity of each female was 91.58 under 25℃ condition.The developmental models of various instars with temperature were given as follows:100/N=30/1+EXP(5.799-0.2719T) for instar one 100/N=59/1+EXP(3.636-0.1842T) for inatar two 100/N=50/1+EXP(2.834-0.1937T) for instar three 100/N=44/1+EXP(3.321-0.2091T) for instar four 100/N=11/1+EXP(4.230-0.2121T) for whole generation.