The hydrogen atom transfer reaction between substituted methane, $CH_3X,$ and its radical, $CH_2X(X=H,F,CH_3,CN,OH;and;NH_2$ was studied by MINDO/3 method. The transition state(TS) structure and energy barriers were determined and variation of the transition state and of the reactivity due to the change of X were analyzed based on the potential energy surface characteristics. It was found that the greater the radical stabilization energy. the looser the TS becomes; the TS occurs at about 15% stretch of the C-H bond, which becomes longer as the radical stabilization energy of $CH_2X$ increasers. The intrinsic barrier, ${Delta}E*_{x.x},$ of the reaction with X was found to increase in the order $H