Abstract: The current design formula for the critical shear stress in JGJ99-98(Technical specification for steel structure of tall buildings) is applied mainly to the design of closely-stiffened plates. However, in practice, the steel shear walls are often stiffened with 1 or 2 longitudinal stiffeners. This paper presents a new study on the elastic buckling of the sparsely-stiffened plates under shear loading. More than 1,600 models are analyzed with the 3-D finite element method (FEM). The plates transversely stiffened with only 1 and 2 longitudinal stiffeners are analyzed. Formulas are presented, comparisons with the numerical results show that the accuracy is good and the formers are reasonably conservative. And the formulas can be applied to practical engineering.