Objective      To establish a new experiment method for recording visual cortex electrical activity through flexible microelectrode array being implanted on the  duramater endocranium above visual cortex

and compare the difference between the visual evoked potential (VEP) evoked by black and white flare and that evoked by black and white checker.     Methods      A total of 5 health adult cats of both sexes were anesthetized

and artificially ventilated by breathing machine. Then flexible microelectrode array designed by our group was implanted on the epidural area outside of visual cortex location region.The results of visual cortex electrical activity evoked by without any visual stimulus or with visual stimulus was compared in order to record VEP. Then flash (black and white flare

F) and graphic (black and white checker

P) visual stimuli were given to record VEPs.     Results      The microelectrode array was implanted on the epidural area outside of visual cortex location region by the minimally invasive surgery. Valid VEP records were obtained by flexible microelectrode array in the epidural area. The valley-peak value of P-VEP was higher than that of F-VEP (P0.01). The delitescence of valley and peak of P-VEP was longer than that of F-VEP (P0.05

0.01).     Conclusion      Our microinvasive surgery procedure to implant and fix flexible microelectrode array on the duramater endocranium  above visual cortex is of good adaptivity and reproducibility. The array is feasible to record VEP. VEPs evoked by black and white checker stimuli is better than those by flash light stimuli.