There are two contents in this paper:one is solve the control differential equation of box girder s shear lag by DQ method,the other is rules of the shear lag for single-box-multiple-cell box girders.

• 本文主要探讨了两个方面的内容：用DQ法求解箱梁剪力滞控制微分方程；单箱多室箱梁剪力滞分布规律。