Abstract: Effects of NBP on liability of stroke,life span and neurological deficits followingstroke were studied in stroke prone spontaneously hypertensive rats(SHRsp).The SHRsp rat was kepton 1% NaCl solution as drinking water and was fed 15 g soft foed containing 0.6～0.8 g NaCl perday.Total NaCl intake for one rat was 1.1～1.3 g per day.After the onset of stroke,tap water andnormal foed was given instead of that containing NaCl.The neurololgical deficits were evaluated by aspecially designed scoring system,These symptoms were divided into 4 degrees(1～4).Grade 1.stress(mild).Grade 2. forelimb or head twitch or with stress(severe).Grade 3.hemiparalysis,bodyinclined or disabled.Grade 4.paralysis,tremor or convulsion。Blood presSure,heart rate and bodyweight were measured once every 2 weeks.The weights of heart,brain and kidneys were alsomeasured。The results show that NBP pre-treatment at the dose of 100 mg·kg^-1·d^-1 po delayed the onsetof stroke.So,like nimedipine,NBP showed a stroke preventive action in SHRsp rats.In addition,treatment with NBP 100 mg·kg^-1·d^-1 po after the onset of stroke,the life span was prolonged andthe score of neurological deficit decreased significantly.Because high blcod pressure can not be loweredby NBP treatment,therefore,the protective effect against stroke can not be explained by the effect ofhyDotension,No change was found in BP,HR and the organ weight.The results indicate that NBP isexpected to be useful in the treatment of stroke.