The　excess　amounts　of　K　and　Na　in　precursor　solutions　are　very　important　for　the　phase　structure　and　performance　of　(K0.48Na0.52)NbO3　(KNN)　thin　films　because　of　their　volatilization　loss.　However,　there　are　no　identical　opinions　have　been　reported　that　could　describe　which　element　is　easily　volatile.　In　this　paper,　different　excessive　amounts　of　K　and　Na　are　added　simultaneously　in　precursor　solutions,　the　lead-free　KNN　thin　films　are　prepared　by　metallorganic　compound　decomposition　(MOD)　method.　Through　comparison　of　phase　structures,　dielectric　properties,　J-E　characteristic　and　ferroelectric　P-E　hysteresis　loops,　the　effects　of　chemical　componential　fluctuation　of　K　and　Na　on　properties　of　KNN　thin　films　are　discussed　systematically.　(C)　Crown　Copyright　2011　Published　by　Elsevier　Ltd　and　Techna　Group　S.r.l..　All　rights　reserved.