Abstract: Differential Scanning Calorimetry and Small Angle X-ray Diffractometry were used to characterize the phase transitions in lamellar liquid crystal systems containing water,alkyl polysorbates,sorbitan esters,stearyl alcohol and oil.The order-disorder transition temperatures of the gelled O/W and W/O globular onion lamellar phases L_O1 and L_O2 and planar gelled lamellar phase L_β were measured as a function of system compositions.The results confirm that stearyl alcohol plays an important role in stabilizing the liquid crystalline phases,and the optimal stabilization of the globular(onion) phase is obtained at a surfactant to alcohol ratio of 1:1.Decreasing this ratio leads to the appearance of a planar phase coexisting with the onion phase and to a separate stearyl alcohol phase.The difference in transition temperature between the onion L_O and planar L_β phases suggests that these phases have different compositions.Decreasing the polarity of the oil extends the melting range of the L_β phases,but also increases the degree of heterogeneity of liquid crystal phase.