This study examined the association of cytokine gene polymorph isms with intrahepatic bile duct wall fibrosis in human clonorchiasis. A total of 240 residents in Heilongjiang, China underwent ultrasonography, blood sampling, and stool examination. Single nucleotide polymorphism (SNP) sites for $IFN-{gamma}$ (+874 T/A), IL-10 (-1,082 G/A, -819 C/T, -592 C/A), $TNF-{alpha}$ (-308 G/A), and $TGF-{eta}1$ (codon 10 T/C, codon 25 G/C) genes were observed with the TaqMan allelic discrimination assay. No significant correlation was observed between individual cytokine gene polymorphisms and intrahepatic duct dilatation (IHDD). Among individuals with clonorchiasis of moderate intensity, the incidence of IHDD was high in those with $IFN-{gamma}$ intermediate-producing genotype, +874AT (80.0%, P=0.177), and in those with $TNF-{alpha}$ low-producing genotype, -308GG (63.0%, P=0.148). According to the combination of $IFN-{gamma}$ and $TNF-{alpha}$ genotypes, the risks for IHDD could be stratified into high (intermediate-producing $IFN-{gamma}$ and low producing $TNF-{alpha}$), moderate, and low (low-producing $IFN-{gamma}$ and high producing $TNF-{alpha}$) risk groups. The incidence of IHDD was significantly different among these groups (P=0.022): 88.9% (odds ratio, OR=24.0) in high, 56.5% (OR=3.9) in moderate, and 25.0% (OR=1) in low risk groups. SNP of $IFN-{gamma}$ and $TNF-{alpha}$ genes may contribute to the modulation of fibrosis in the intrahepatic bile duct wall in clonorchiasis patients.