Abstract: In order to evaluate the activity and potential application of acetylcholinesterase inhibitors from Oxytropis glabra DC.and Swainsonia salsula (Pall.) DC.,the inhibition mechanism and kinetics were investigated in this study.Each extract was prepared using different polarity solvents associated with ultrasonic assisted extraction.In addition,improved Ellmans' colorimetric method was employed to exploit the acetylcholinesterase inhibition activity and kinetics.Results showed that the chloroform extracts of both root and leaf of  O.glabra and the leaf of S.salsula demonstrated higher AChE inhibitory activities over other extracts  with the IC₅₀ values of 0.67 mg/mL,1.69 mg/mL and 0.17 mg/mL,respectively.The inhibition mechanism of chloroform extracts from leaf of these two plants are both mixed type reversible inhibition.

Key words: extract, acetylcholinesterase, inhibition mechanism, kinetics