Laryngopharyngeal reflux(LPR) is one firm of the gastroesophageal reflux diseases(GERD). It is known to cause various kinds of otolaryngologic symptoms such as hoarseness, foreign body sensation in throat, chronic throat clearing, chronic cough, etc. Disease entities diagnosed by otolaryngologists as posterior laryngitis, globus pharyngeus should be suspected as LPR-related diseases. In this multi-center trial, we tried to evaluate the effect of cisapride(10mg tid) on LPR-related symptoms as the part I study(CIS-KOR-051) in 19 centers, and as the part II study(CIS-KOR-052) comparative evaluation of effect between cisapride(10mg tid) and ranitidine(150mg bid) on LPR-related symptoms in 4 centers. In part I study, efficacy of cisapride on LPR-related symptoms after 4 weeks was 53.5% and that of after 8weeks was 77.9% in per protocol(PPA) analysis group. In part II study, efficacy of the cisapride was much better than that of ranitidine not only from 8 weeks trial(p<0.001) but also from 4 weeks trial(p<0.021) in PPA group. In the multiple logistic regression analysis among the parameters which affect the efficacy of the treatment, cisapride prescribed group showed 10 times greater than that of ranitidine prescribed group(p<0.0001, Odds ratio : 10) in PPA group. LPR was proved by 24Hr double probe pHmetry in 13 patients out of 19 patients tested(68.4%). Thus these results indicated that inducing the improvement of motility functions could affect the amelioration of the LPR-related symptoms much better than reducing acid secretion from the stomach. And maybe it suggests that LPR-related symptoms mainly developed by the reduced motility functions of the esophagus and/or delayed gastric emptying.