Objective to develop a rotation monitoring device to monitor animal rotation during experiments.Methods Use serial port controls,USB and rotary encoder et al.modern computer cience,with the combination of traditionally experimental methods and the software designed in VC language.Results A mini animal rotation monitor was developed,which could continuously monitor animal rotation and intelligently display the rotaion.conclusion Statistic analysis of experimental data proofs the rationality and effectiveness of the apparatus.The rotational behavior monitor can play an importance role in research into the pathogenesis of Parkinson's Disease(PD)and screening the anti-PD drugs.