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  • 1 Department of Applied Physics Nagoya University 464-01 Nagoya Japan
  • 2 Department of Physics Sapporo Medical College 064 Sapporo Japan
  • 3 Department of Physics Tokyo Institute of Technology 152 Tokyo Japan
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Using an ac calorimetric method, detailed behaviour of the heat capacity in dipalmitoyl-phosphatidylcholine-cholesterol system was studied in the cholesterol concentration less than 5 mol%. It was revealed that the heat capacity near the main transition was composed of at least four anomalies, i.e., multipeak took place in the heat capacity. This fact indicates that a simple theory explaining coexistence of two phases in two component systems does not work in the multipeak region. Then, relation between the multipeak heat capacity and the change of the ripple structure with the cholesterol concentration should be taken into account, when we consider thermodynamical behaviour of the systems.