Follistatin play vital role in biological processes which includes cell proliferation, differentiation, and skeletal muscle growth. The present study was carried out to study polymorphism of exon4 of follistatin gene and its association with body weight in PD-1, a broiler line of chicken. A product of 225 bp of exon-4 was amplified and structural variability was studied using polymerase chain reaction, single strand confi rmation polymorphism and sequencing method. This study revealed that the FSTN gene was monomoprphic at exon4. Growth data was also analyzed, the growth performance of male and female differed

significantly at six week of age.