In order to investigate the effect of polymorphism of the first exon of OC-116 gene on eggshell quality,Changshun Blue-eggshell chicken was used as materials and the single nucleotide polymorphism(SNP) in the first exon region of OC-116 gene was detected by the direct sequencing of PCR products.General linear model was used to analyzed the genetic effects of polymorphic loci on shell quality of Changshun Blue-eggshell chicken. The results showed that two moderately polymorphic and fully linked SNPs were detected in exon 1 of the OC-116 gene,g.45667632 T>C and g.45667671 G>A,respectively,and three genotypes were generated.Chi-square(χ2) test found that the genotype distribution of the two SNPs did not deviate from the Hardy-Weinberg equilibrium(P>0.05),and there were two haplotypes and three diplotypes in the two SNPs.The genotypes CC,AA and diplotype H2H2 were significantly higher in egg quality than genotypes TT,GG and diplotype H1H1 (P<0.05);the genotypes TT,GG and diplotype H1H1 were significantly higher in egg shape index than genotypes CT,AG and diplotype H1H2 (P<0.05);the genotypes CT,AG and diplotype H1H2 were significantly higher in eggshell strength than genotypes TT,GG and diplotype H1H1(P<0.05).Taken together,genotypes CC,AA and diplotype H2H2 are favorable genotypes and diplotype for improving eggshell quality,revealing that g. 45667632 T>C site and g.45667671 G>A site may serve as marker sites for shell trait selection.