Abstract: The heavy metals pollution is one of the ecological problems which have been paid close attention to Spodoptera exigua Hübner, one of the key pests on vegetables and cotton in the Yangtze River and its southern area in China, has broken out more frequently in recent years. In this study, accumulation of Pb²⁺ in S. exigua and its excretion were detected when fed with artificial diets with different Pb²⁺ concentrations (0.3, 1.2, 4.8, 19.2 and 76.8 mg·kg^-1, respectively). Life table was constructed according to the survival and growth of different stages of S. exigua. The effect of lead on three successive generations of beet armyworm was studied using the life table in the laboratory. It was found that the Pb²⁺ contents were significantly different when S. exigua was reared at different Pb²⁺ concentrations in the same generation in a significant dosedependent manner. The concentration of Pb²⁺ increased with prolonging the stress time at the same time. The Pb²⁺ concentrations at the three developmental stages of beet armyworm followed the order of larvae > adult > pupa. The beet armyworm could excrete heavy metals by means of faeces, prepupa exuviate and puparium, and the concentrations of Pb²⁺ in faeces and prepupa exuviate were far higher than in puparium. According to the survival rates of different developmental stages, the female ratios and the egg numbers, the laboratory population life table was constructed. It showed that low doses of Pb²⁺ promoted the growth of the population, and high doses inhibited the growth, and the index of population trend (I) declined more rapidly with the increase of stress time. The study could provide references for longterm and objective assessment of heavy metal hazard and its effect on the populations of important agricultural pests.