The natural life tables of diamonthback moth (DBM), Plutella xylostella under pesticides treatment were constructed, and the construction method of item "pesticide" was particularly discussed. The life tables indicated that the indices of population trend (I) under the treatment with 80% Dichlorvos EC 1000x and the contrast were 0.7796 and 1.4804, respectively, showing that Dichlorvos had some control on DBM. But, Dichlorvos had some effects on natural enemies of DBM. The decrease of parasitism rate at pupa stage was most obvious, which indicated that Dichlorvos had some effects of killing and wounding on the natural enemies of DBM.