Effects of the multilayer heterostructures as the feedback end facets and quantum well structure as the active medium on the lasing behavior in the vertical cavity surface emitting laser (VCSEL) have been analyzed theoretically and systematically. It is shown that the degree of phase matching and the effective length of the distributed reflector have prominent effects on the laser characteristics, and the available low threshold VCSEL may not be due to the microcavity effect. The possible ways to improve the design and the device characteristics have been proposed, both for low threshold and simplified device technology, and for satisfying the condition of microcavity effect in VCSEL.