Abstract: The activity of acetylcholinesterase (AChE) and carboxylesterase (CarE) in Pardosa pseudoannulata body were systemically studied in different control rice field and its different development stage by ultraviolet spectroscopy. The result showed that specific activity of AChE and Km value at different development stage of chemical control rice field population (CCP) were higher than that at different development stage of bio-control rice field population (BCP).In total development process of Pardosa pseudoannulata, specific activity of AChE at instar body was highest, the least at ovum stage.It dedicated that specific activity of AchE exists difference at different development stage of Pardosa pseudoannulata. On the contrary, specific activity of CarE at different development stage of CCP was higher than that at corresponding development stage of BCP,and specific activity of CarE at instar stage was higher than that at adult stage. Kinetics studies showed that Km values of CarE at different development stage of BCP were larger than that at corresponding development stage of CCP. The result indicated that Pardosa pseudoannulata may raise the resistance to some chemical pesticides in chemical control rice field.