Objective To investigate the number and distribution of un-repaired cleft lip/palate patients in Gansu province. Methods A census was conducted by staff members of the health system and Population and Family Planning Committee (PFPC) in Gansu province. Standardized -Questionnaires were administered to collect demographic, domestic and diagnosis-related information. Results In 2008, the total number of un-repaired cleft lip/palate patients was 4675,with a detection rate of 1.84/10 000 in Gansu province. Rates of detection were higher in males (2.11/10 000), young age group(4.86/10 000), rural areas(2.23/10 000),poor counties(2.19/10 000)than in females(1.43/10 000), medium (0,97/10 000)/old age group(0.68/10 000), township areas (0.62/10 000), or richer counties (1.35/10 000). Among all the cities and prefectures of Gansu,Baiyin city (2.7/10 000) had the highest while Jinchang city (0.7/10 000) had the lowest prevalence rates. Conclusion Un-repaired cleft lip/palate had been a disease burden to Gansu province,especially in the rural area and poorer counties.