The myonectin and myostatin genes are two genes involved in the regulation of muscle growth. Myostatin is a suppressor of muscle growth, while myonectin is a muscle builder that can help with growth. The purpose of this study was to investigate the effect of resistance training in combination with L-arginine supplementation on the expression of myonectin and myostatin genes in the soleus muscle of young male rats. Thirty two young male Wistar rats were randomly divided into 4 control groups, supplement (L-arginine), combined (resistance exercise + L-arginine supplement) and exercise (resistance exercise). Resistance training consisted of eight weeks of ladder training with moderate intensity (70% of MVCC) and five days a week. The rats in the L-arginine supplement group and the supplement + exercise group received L-arginine supplement after exercise at the same times as the exercise (5 days a week for 8 weeks). kg was gavage to the exercise and supplement group. The relative expression of myonectin and myostatin genes was obtained using the Real-time PCR method. The data were analyzed using two-way analysis of variance and post hoc test. The results of the two-way analysis of variance test showed that the expression of myonectin gene in the soleus muscle of young male rats in the groups trained with and without L-arginine supplementation was significantly higher (P=0.001) and the expression of myostatin gene (P=0.002) was significantly lower than in the untrained groups with and without supplementation. These molecular adaptations suggest enhanced muscle growth potential and reduced inhibitory signaling, creating a favorable environment for muscle maintenance and development. The combination of resistance exercise and L-arginine supplementation may therefore be an effective strategy to promote muscle hypertrophy and prevent muscle atrophy in young skeletal muscles. Further studies are warranted to clarify the mechanisms underlying these effects and to explore their clinical relevance.