【Abstract】 Objective To verify the effect of simvastatin on the population dynamics of Blattella germanica. Methods Two groups of B.germanica were reared with feedstuff containing 0.001% simvastatin and common feed, respectively. The population quantity of different development stages of B.germanica and their constitution ratio were investigate after breeding for different time. Results The quantity of adult cockroaches with oothecae in the tested group reduced gradually after treatment for two months, six months and eight months, respectively. Accordingly, the quantity of male and female adult cockroach also decreased gradually. The nymphae quantity after treated for four months was two times than that after treatment for two months. However, it decreased rapidly in the sixth month, and the quantity of female adults and adults with oothecae reduced to zero in the eighth month. The quantity of male adults and nymphae was 2 and 15, respectively. The quantity of adults with oothscae was all higher than the initial number after they were bred with common feed for two months and six months. But in the forth month, it decreased a little compared to the initial number. And, it was basically equal to the initial number in the eighth month. With the decrease of the adults with oothecae, the quantity of male and female adults also reduced gradually. Similar to the tested group, the nymphae quantity in the control group was the highest after breeding for four month, and then it gradually decreased. In the eighth month, there were 78 nymphae, 5 adult cockroaches with oothacae, 8 female adults and 12 male adults. Conclusion B.germanica would lose the capability of its population restoration after breeding with feed containing 0.001% simvastatin for eighth months.