Lactulose hydrogen breath test has been used for rneasurement of orocecal transit time (OCTT) because of its non invasiveness and simplicity. Recently, the lack of reproducibility of OCTT which measured by hydrogen breath test using water diluted lactulose resulted in the need to develop a new semisolid or solid meal combined lactulose hydrogen breath test. We measured OCTT in 47 norrnal subjects(male 17, female 30, age 24 69 years, average 35.5 years) after ingestion of semisolid meal including potato soup and lactulose syrup 20g. OCTT was defined as the time from test meal ingestion to a sustained increase of more than 10pprn above the baseline in end expiratory hydrogen concentration with 10 minutes interval for 3 hours. OCTT was 79.2+11.9(mean+SD) minutes in male, 81.5+15.2 minutes in female, and average 81.9+13.3 minutes. Although there was no significant difference according t,o sex, OCTT in sixth and seventh decades were delayed compared to third decades(P<0.05). These results will be useful for comparison of OCTT in different group of patients.(Korean J Gastro- enterol 1994; 26: 619 624)