Whistler waves are important in scattering and accelerating electrons in space. In the supercritical regime where the upstream Alfvén Mach number is above the so-called whistler critical Mach number, phase standing whistler waves can be excited and confined in the foot of the quasi-perpendicular shocks. On the other hand, in the subciritical regime whistler wave trains are emitted toward the upstream of the shock. However, the electron acceleration efficiency related with the whistler critical Mach number is not understood well. Here we report new results from several 1D particle-in-cell simulations of quasi-perpendicular shocks above and below the whistler critical Mach number. In the subcritial regime, the simulation showed that high energy electrons penetrate upstream, and the density profile is similar to the standard diffusive shock acceleration. On the other hand, in the supercritical regime, the high-energy electrons are generated locally in the narrow regin of the foot or overshoot magnetic field. This is similar to electron spike events at the Earth’s bow shock and interplanetary shocks. Our result will give a new insight into the understanding of electron acceleration at collisionless shocks.