BaxSr1-xTiO3(BST)　film　has　a　good　foreground　as　an　important　ferroelectric　film　in　DRAM,　pyroelectric　infrared　detector,　film-ceramic　capacitor　and　film　sensor,　etc.　due　to　strong　nonlinear　dielectricity,　small　leak　current　and　fatigue　characteristics.　Ba0.7Sr0.3TiO3　ferroelectric　films　were　prepared　by　water-based　sol-gel　process　in　this　paper.　By　changing　techniques　condition　of　preparation,　techniques　that　homogeneous　and　crack-less　ferroelectric　films　were　prepared　with　water-based　sol-gel　process　was　searched.　The　structure　and　properties　of　sol-gel　and　the　films　were　analyzed　by　available　testing　measure　such　as　optical　microscopy　(OM),　XRD,　SEM　and　TEM.　The　influences　of　hydrolysis-polymerization　process　and　degree　of　hydrolysis　on　production　of　sol-gel　were　investigated.　The　effects　of　process　condition　on　properties　of　films　were　studied.　The　influences　of　heat　treat　condition　to　crystallinity　were　discussed.　The　results　show　that　the　higher　concentration　of　water-based　precursor　solution　is　beneficial　to　form　a　uniform　film.　The　optimum　processing　parameters　for　preparing　films　are　as　follows:　concentration　of　precursor　solution　is　0.56　mol/L;　pH　value　is　5.5;　aging　time　is　48　similar　to　72　h.　Film　sample　with　good　performance　can　be　obtained　under　the　optimum　conditions.　The　XRD　analysis　indicates　that　film　had　been　perovskite　after　650　degrees　C　treatment.