  We study the weak Galerkin finite element method for Stokes problem. A new
weak Galerkin finite element velocity-pressure space pair is presented which
satisfies the discrete inf-sup condition. Based on this space pair, we
establish a stable weak Galerkin approximation scheme without adding any
stability term or penalty term. Then, we further derive the optimal error
estimates for velocity and pressure approximations, respectively. Numerical
experiments are provided to illustrate the theoretical analysis.
