The aquifer systems stand for ODe ofthe main supplies ofgrnundwater in lhe SIo Paulo State.lt'srepresentedbytheaquifersedimentarysystemsandtbeaquiferfracturedsystemswitbvariableIithology,ooveringanareaof247.898km2.The bydrngcocbemical studies carricd out berewith, were inteDded to investigate, in a regional basis, lhe following topics: lhe charac:tcriLuion of tbe diffcrcnt hydrogeochemical types and lheir intcrrclations; lhe evolution of lhe groundwatu's cbemical composition a10ng lhe percoJation in lhe aquifer; lhe hydrogcocbemical zoning and lhe discrimination of chemical types according to lhe hydrogeochemicaJ anomaly; tbe dctermination of tbe watef quaJity according to lhe diffettnt uses and its chemical attack polentiaJ to lhe well equipment ln this study 1.364 grnundwater cbentical analyses were employed The hydrogeochcmical data intetpretation was basod on: data analyses pI"OCe55ing, isovalucs maps and cartographicintegration.The groundwater have.generally, a very low salinity contem: and belong to two dominant cbemicaJ.typCS: tbe calcium hicaJbonale type anel lhe sodium bicarbonatc type.The principal treDd in lhe regional hydrogcocbemical evolution according to ionic increase is frnm nortbeast to southwtsI: (Botucatu aquifer system).The hydtogeochemical anomaiy (F) propose relationship witll structurallinc:aments.Concerningtbegroundwaterchemicalqualityforthevarioususesthesc: watcrscoroply