The shear design formula for seismic shearwalls in the Chinese standard (Code for Design of Concrete Structures) have not been verified by tests yet, In order to compensate for it, the authors undertake the task of testing on the shear behavior of seismic shearwalls organized by the Code association. After discussing on the particular conditions controlling tests and philosophy in specimen designing, the results of the first group of tests on the seismic shear behavior of shearwalls, which are I-shaped and with relatively large scale and axial force ratio of 0.2 and tested under reversed cyclic horizontal forces, are introduced. The results are analyzed and discussed.