Three plant extracts of Nerium oleander, Eucalyplus melliodora and Azadirachta indica at 10 and 20% concentrations were tested against adult individuals of Monacha cartusiana land snail under laboratory conditions to show their toxicity effects on the activity levels of GOT, GPT, AchE, GST, Alpha Estrase, Beta Esterase and phenolase enzymes. The results indicated that N. oleander extract had the highest effect on six enzymes expect AchE which was more affected with E. melliodora extract. Different five concentrations of N. oleander leaves extract were used against adult stage of the tested animal, mortality percentages and LC25, LC50 and LC90 were recorded. Based on LC50 of the tested extract caused high effectness on some aspects of M. cartusiana life cycle (number of eggs, oviposition inhibition, depth of eggs, weight of eggs, incubation period and hatchability percentage) under laboratory conditions.