The purpose of the study to find out the Effect of aerobic and Pranayama training on Forced Expiratory Volume in one second and Peak Expiratory Flow Rate of prepuperty boys. To achieve this purpose of the study has selected 30 school boys on random sampling technique. The selected subjects were divided into three groups namely experimental group I & II, control group III. The training programme was included pre test and post test session over a period of 12 weeks which was considered to be adequate time for the change among selected variables. The training was given for six days in a week. The subjects of yoga, aerobic training and control group were tested on Forced Expiratory Volume in one second and Peak Expiratory Flow Rate with wet spirometer. The date were collected from the three groups before and after the experimental period and analysed by the analysis of variance(ANOVA) and analysis of covariance (ANCOVA) to find out the significant difference. The level of significance was fixed at 0.05 levels. If the “F” value for the final test is significant, scheffe’s post hoc test was used to find out the significant mean difference between the groups. The experimental groups showed significant improvement Forced Expiratory Volume in one second and Peak Expiratory Flow Rate than the control group. The aerobic exercise group showed better improvement on Forced Expiratory Volume in one second and Peak Expiratory Flow Rate than the yoga group.