The　aim　of　this　study　is　to　select　organic　solvents　that　dissolve　large　numbers　of　poor　water-soluble　chemicals　including　environmental　contaminants　in　cell　transformation　assay　and　provide　reference　for　solvents　vehicle　selection.　The　cytotoxicity　of　eight　commonly　used　organic　solvents-ethanol,　methanol,　acetone,　isopropyl　alcohol,　1,2-propanediol,　glycerin,　acetic　ether　and　dimethyl　sulfoxide　(DMSO)　towards　Balb/3T3　and　293T　cells　has　been　studied　by　CCK-8　assay.　The　results　indicated　that　the　cytotoxicity　increased　significantly　with　the　increasing　concentration　of　solvent　compared　to　the　control　group,　and　it　showed　a　dosage-response　relationship.　Methanol,　DMSO　and　ethanol　exhibited　much　less　cytotoxicity,　which　was　slightly　different　between　the　two　cell　lines.　The　concentrations　with　70%　of　cell　viability　were　3.70%,　1.40%　or　1.20%　(v/v)　in　Balb/3T3　cells　and　2.20%,　1.40%　or　0.80%　(v/v)　in　293T　cells,　respectively.　The　five　other　solvents　displayed　much　greater　cytotoxicity,　the　concentrations　with　70%　of　cell　viability　were　much　lower.　The　concentrations　of　acetic　ether　and　acetone　with　70%　of　cell　viability　were　below　0.20%.　While,　the　difference　of　concentrations　of　isopropyl　alcohol,　glycerin　and　1,2-propanediol　with　70%　of　cell　viability　was　2-4　times　between　the　two　cell　lines.　The　cell　viability　percent　in　solvents　with　little　cytotoxicity　should　be　above　90%.　Methanol　at　0-1.0%　(v/v)　and　DMSO　at　0-　0.3%　(v/v)　presented　much　less　cytotoxicity　towards　Balb/3T3　cells,　the　cell　viability　percent　was　about　95%.　Ethanol　at　0-0.3%　(v/v)　showed　the　least　cytotoxic　effect　towards　293T　cells,　the　cell　viability　percent　was　approximately　95%.　Therefore,　methanol/DMSO　and　ethanol　might　be　compatible　solvents　vehicle　towards　Balb/3T3　and　293T　cells,　respectively.　Methanol　and　ethanol　were　much　better　than　DMSO　towards　the　two　cell　lines.　In　addition,　the　selection　of　solvents　vehicle　might　be　affected　by　cell　type.　©　2011　IEEE.