Microstructure characteristics, phase transition, and electrical properties of (Na0.535K0.485)(0.926)Li-0.074(Nb0.942Ta0.058)O-3 (NKN-LT) lead-free piezoelectric ceramics prepared by normal sintering are investigated with an emphasis on the influence of sintering temperature. Some abnormal coarse grains of 20-30 mu m in diameter are formed in a matrix consisting of about 2 mu m fine grains when the sintering temperature was relatively low (980 degrees C). However, only normally grown grains were observed when the sintering temperature was increased to 1020 degrees C. On the other hand, orthorhombic and tetragonal phases coexisted in the ceramics sintered at 980 degrees-1000 degrees C, whereas the tetragonal phase becomes dominant when sintered above 1020 degrees C. For the ceramics sintered at 1000 degrees C, the piezoelectric constant d(33) is enhanced to 276 pC/N, which is a high value for the Li- and Ta-modified (Na,K)NbO3 ceramics system. The other piezoelectric and ferroelectric properties are as follows: planar electromechanical coupling factor k(p)=46.2%, thickness electromechanical coupling factor k(t)=36%, mechanical quality factor Q(m)=18, remnant polarization P-r=21.1 mu C/cm(2), and coercive field E-c=1.85 kV/mm.