This paper proposes prediction methods of the maximum in-plane shear force acting on floor slab for transmitting to plane frame the inertial force due to earthquake. And, time history response analysis are conducted, in order both to confirm prediction methods and to verify effects of structural parameters on the maximum in-plane shear force. As a result, following conclusions can be obtained; (1) the maximum in-plane shear force converges to the value of the rigid floor slab after indicating the maximum value, as in-plane stifness of floor slab becomes larger, and (2) proposed prediction methods agree with time history responses qualitatively.
