The present study was conducted to investigate the existence of polymorphism at transferrin (Tf) locus in the Carp (Cyprinus carpio). A polyacrylamide gel electrophoresis (PAGE) under alkaline condition method was used to distinguish Carp Tf alleles. Analysis of 116 samples revealed that all animals were polymorphic, showing many genotypes with clear biodiversity in the Tf gene. Seven Tf genotypes consisting of 4 homozygote types (CC, DD, FF and GG) and two heterozygote types (CD, DG and FG) were detected. These fractions are controlled by codominant autosomal genes according to the Mendelian laws of inheritance. The highest gene frequencies were calculated such as 0.50 for Tf D, 0.26 for Tf F and 0.12 for C and G. Thus, carp assemblages consistently tended to be more predominant to D allele. Differences between expected number and observed number for transferrin genotypes were no significant. Polyacrylamide electrophoresis, the technique employed in this study, allows rapid and efficient screening for the presence of polymorphism in Tf.