This study studied the use of ERCP and nasobiliary tube in the diagnosis of fungal infection of biliary tract and the efficacy of combined use of local administration via nasobiliary tube and intravenous antifungal treatment for severe biliary tract fungal infection. 5 patients in our series,with age ranging from 47 to 68 y (mean 55.8), were diagnosed as having mixed bacterial and fungal infection of biliary tract as confirmed by smear or/and culture of bile obtained by ERCP and nasobiliary drainage. Besides routine anti-bacteria therapy, all patients received local application of fluconazole through nasobiliary tube and intravenous administration of fluconazole or itraconazole in terms of the results of in vitro sensitivity test. The mean duration of intravenous fluconazole or itraconazole was 30 days (24-40 days), and that of local application of fluconazole through nasobiliary drainage tube was 19 days (8-24 days). During a follow-up period of 3-42 months, all patient's fungal infection of biliary tract was cured. It is concluded that on the basis of typical clinical features of biliary tract infection, fungal detection of smear/culture of bile obtained by ERCP was the key for the diagnosis of fungal infection of biliary tract. Local application antifungal drug combined with intravenous anti-fungal drugs might be an effective and safe treatment for fungal infection of biliary tract.