The lead-free piezoelectric ceramics (1-x)(K0.5Na0.5)NbO3-xLiNbO3(abbreviated as KNLN) were synthesized by a traditional solid state reaction. The effects of Li+ on the sintering characteristic,the phase structure and piezoelectric properties of KNLN ceramics were investigated. The sintering temperature of KNN-based ceramics is decreased by doping Li+ and the range of the sintering temperature is narrow. The KNLN ceramics exhibit an enhanced piezoelectric properties with the piezoelectric constant d33 value of 180-200 pC/N,The electromechanical coupling coefficients kp is 35%-40%. The results show that (1-x)(K0.5Na0.5)- NbO3-xLiNbO3 (x=0.05,0.06) is a promising high-temperature lead free piezoelectric ceramic.