A high efficiency 1064 nm Nd:YVO4 laser which is in-band pumped from high Stark level of ground state to upper laser level by another Nd:YVO4 laser operating at 914 nm is demonstrated. To overcome the drawback of low optical-optical conversion efficiency induced by poor pump absorption, the influences of doping concentration, temperature and length of laser gain medium on pump absorption and laser conversion efficiency are investigated in detail. On this basis, a high optical-optical efficiency of 56.9% is achieved by using Nd:YVO4 crystal with length of 20 mm as gain medium. The optical-optical conversion efficiency of the Nd:YVO4 laser in-band pumped from high Stark level of ground state at 914 nm reaches a practical level comparable to that of traditional pumping.