Perovskite oxides were typically considered as the electronic and ionic conductors for application in the electrolytes for solid oxides fuel cells (SOFCs). Recently, LaFeO3-based systems were mainly focused on the electrochemical property for the anode of Ni/MH batteries in our previous work, and the exciting results of their electrochemistry capacity and cycle life examination exhibited much scientific values for further investigation. In the present work, the effects of A (La)-site or B (Fe)-site metal ions doped and substituted on the fundamental properties of these materials were calculated by a first-principle approach. In conjunction with the experimental results, the microscopic mechanisms of the doped or substituted effect were discussed and elucidated. On the other hand, the hydrides of LaFe(Cr)O-3 were established and computed to explore the nature of electrochemical behaviors of these perovskite oxides.