Exercise training induces numerous muscular and cardiovascular changes but the mechanism on the molecular basis is still not understood. microRNA molecules (miRNAs) have been recently identified as essential intracellular mediators may help in muscle cells hypertrophy. miR-206, a muscle-specific miRNA that is up-regulated by exercise affecting muscular hypertrophy. The purpose of this study was to identify The effect of Cross Training to assess miRNA-206 concentrations in basketball players at rest and after a proposed program during transitional period as indicator of muscle hypertrophy for basketball players. Where the (number of weeks training program Proposition 6 weeks, the number of training units 18 and training units time 90 minutes), The researcher used the experimental design with one groups of pre-and post-measurements to a sample of 10 players selected by intentional way. The most important results showed on the effectiveness of the proposed program, Where the cross training have a positive impact on the levels of miRNA-206 after effort either before or after training basketball program with maximum elevation in post-exercise after program To increase the level of physical efficiency. It is concluded that microRNA (miRNA) molecules are essential intracellular mediators of numerous biological processes including angiogenesis, inflammation, and mitochondrial metabolism with resultant muscular hypertrophy. The researcher recommends application the suggested training program because it has a positive effect in improving the skillful performance for juniors basketball.