This study aims to determine the diversity of growth hormone genes in Sentul chickens using PCR-RFLP. This study used 70 samples of Sentul chicken blood (35 males and 35 females). The research methods are Bodyweight and body weight gain data collection, blood collection, DNA extraction, and PCR-RFLP. Polymorphism analysis included genotype and allele frequencies, Hardy-Weinberg balance, and heterozygosity. The difference in the average body weight against the genotype of the GH|Msp1 gene was tested for the average difference (t-test). The average body weight of DOC - 3 months and body weight gain of DOC - 3 months in male Sentul chickens were significantly different (P <0.05) higher than female Sentul chickens. The GH|MspI gene in Sentul chickens is polymorphic. The Sentul chicken population was in Hardy-Weinberg equilibrium. Heterozygosity in the Sentul chicken population was Ho 0.228, greater than the He value of 0.213. Genotypes (++) and (+-) were significantly different (P<0.05) on body weight and body weight gain of Sentul chickens aged DOC - 3 months. The conclusion of this study, the allele frequency at the GH|MspI Sentul chicken is polymorphic with two genotypes, namely (++) and (+-), and there are two kinds of alleles (+) and (-). Chisquare test results on the GH|mspI Sentul chicken show balance Hardy-Weinberg. Heterozygosity in Sentul chickens showed diversity. The genotype of the GH|Msp1 Sentul chickens with the genotype (++) had higher body weight and body weight gain than those with the (+-) genotype