The present investigation deals with practical calculation for the strength of electric railcar body. A new calculation method for the end shock on underframe was established as a result of the investigations of clashed railcar bodys. Two solutions were obtained on the strength of railcar body considering sideframe as both Vier endeel Rahmen and sandwiched beam. A solution as Vierendeel Rahmen was obtained by modified slopedeflection method, in which the effect of shear deflection and the joint area of each member was considered. Another solution as sandwiched beam was obtained under the assumption that each post in sideframe is substituted for elastic layer in the sandwiched beam. Three factors were found important on the practical strength calculation of electric railcar body, that is, (1) Ratio of the length of overhang to the distance between bolsters, (2) Arrangement of side doorways and (3) Rigidity of posts.