The　physical　properties　of　copper　oxide　high-temperature　superconductors　have　been　studied　extensively,　such　as　the　band　structure　and　doping　effects　of　Bi2Sr2CaCu2O8+delta　(Bi-2212).　However,　some　chemical-related　properties　of　these　superconductors　are　rarely　reported,　such　as　their　stability　in　water-bearing　environments.　Herein,　we　report　experiments　combined　with　ab　initio　calculations　that　address　the　effects　of　water　in　contact　with　Bi-2212.　The　evolution　of　Bi-2212　flakes　with　exposure　to　water　for　different　time　intervals　was　tested　and　characterized　by　optical　microscopy　(OM),　atomic　force　microscopy　(AFM),　Raman　spectroscopy,　transmission　electron　microscopy　(TEM),　and　electrical　measurements.　The　thickness　of　Bi-2212　flakes　is　gradually　decreased　in　water,　and　some　thin　flakes　can　be　completely　etched　away　after　a　few　days.　The　stability　of　Bi-2212　in　other　solvents　is　also　evaluated,　including　alcohol,　acetone,　HCl,　and　KOH.　The　morphology　of　Bi-2212　flakes　is　relatively　stable　in　organic　solvents.　However,　the　flakes　are　etched　relatively　quick　in　HCl　and　KOH,　especially　in　an　acidic　environment.　Our　results　imply　that　hydrogen　ions　are　primarily　responsible　for　the　deterioration　of　their　properties.　Both　TEM　and　calculation　results　demonstrate　that　the　atoms　in　the　Bi-O　plane　are　relatively　stable　when　compared　to　the　inner　atoms　in　Sr-O,　Ca-O,　and　Cu-O　planes.　This　work　contributes　toward　understanding　the　chemical　stability　of　a　Bi-2212　superconducting　device　in　environmental　medium,　which　is　important　for　both　fundamental　studies　and　practical　applications　of　copper　oxide　high-temperature　superconductors.