The aim of this study was to compare the responses of testosterone, cortisol and creatine kinase to two types of resistance training with and without blood flow restriction. For this purpose, 36 gymnast boys aged between 10 and 14 participated in a quasi-experimental research. The subjects (mean weight 37.11 ± 8.11 kg, height 145.16 ± 11.58 cm, body mass index 17.40 ± 1.77 kg/m2) were randomly divided into three groups: control (n=12), traditional resistance training (n=12), and resistance training with blood flow restriction (n=12). Training protocol included three movements: leg extension, elbow flexion and bench press. Blood samples were collected before and half an hour after the training. Dependent t test was used to check the intragroup results and one-way ANOVA and LSD post hoc test were used to evaluate the intergroup results. The intragroup results showed that testosterone variable was not significant in traditional resistance training (P=0.653) and resistance training with blood flow restriction (P=0.107) groups after a bout of training. But cortisol variable significantly increased in both traditional resistance training (P=0.015) and resistance training with blood flow restriction (P=0.015) groups. Also, creatine kinase was significant only in traditional resistance training group (P=0.001). The intergroup results showed that no significant differences in testosterone and cortisol of both types of training between the groups but the difference was significant in creatine kinase (P=0.05). Equal anabolic response in two types of resistance training in this study and less damage index in blood flow restriction group supported the advantage of this type of resistance training to some extent.