In this study, K3Li2-xNb5+xO15+2x (KLN) thin films were prepared by laser-ablated a sintered ceramic target. For an optimum deposition condition, in-situ post annealing method was employed on as-deposited films. XRD measurements showed that KLN films with (310) preferred orientation were obtained on fused quartz substrate. Surface morphology studies indicated that in-situ post annealing could improve the surface quality of KLN thin films. The average transmittance of as-deposited and annealed films in the visible range was nearly 80% to 90%.