Experiments　on　electrical　conductivity　in　aqueous　solutions　of　cationic　gemini　surfactants　as　a　function　of　concentration　and　temperature　were　carried　out,　where　two　species　of　alkyldimethylammonium　bromide　[CmH2m+1N(CH3)(2)　.　Br,　m　=　8,　10,　12]　were　linked　at　the　polar　head　groups　via　a　hydrocarbon　spacer　[(CH2)(s),　s　=2,3,4,6].　Critical　micelle　concentration　(cmc)　was　obtained　from　the　break　point　in　the　curve　of　conductivity　kappa　vs　concentration　c.　The　results　indicate　that　the　trend　of　micelle　formation　of　the　gemini　surfactants　is　significantly　stronger　than　the　corresponding　＂monomer＂,　i.e.　alkyltrimethylammonium　bromide.　The　changes　of　Gibbs　free　energy,　enthalpy　and　entropy　in　the　process　of　micellization　were　evaluated　based　on　a　mass　action　model.　The　results　show　that　micellization　of　the　gemini　surfactants　is　an　entropy　-　driven　process,　which　is　similar　to　conventional　surfactants.　All　plots　of　enthalpy　-　entropy　compensation　exhibit　excellent　linearity.　The　intercept　of　compensation　of　the　gemini　surfactants　decreases　with　the　decrease　of　s　from　6　to　2.　This　implies　that　the　gemini　surfactants　with　short　spacer　chain　tend　to　form　stable　micelles.