Squids and Cuttle fishs are most popular frozen marine products for export. It is therefore necessary to know their thermal properties in the freezing range in order to calculate the applicable freezing time in process. This research focused on; first, designing and improving the proper equipment for measuring their specific heat, thermal conductivity and thermal diffusivity of squid and cuttle fish and second, studying the effects of breeds (Loligo formosana and Sepia pharaonis), conditions of thawing (unthawed and thawed) and temperatures (-401,-301, -181 and -101 C) on their thermal properties. The third part was to determine the relationship between thermal properties and breeds conditions of thawing and temperatures. The specific heat, thermal conductivity and thermal diffusivity of squid and cuttle fish were measured by modified method of mixture, the thermal conductivity probe and the thermal diffusivity plate, respectively. The corresponding specific heat, thermal conductivity and thermal diffusivity of unthawed squid were 0.481-1.146 cal/g C, 1.311-1.567 W/m K and 2.761x10-7 -7.451x10-7 m2/s while the thawed squid were 0.357-1.017 cal/g C, 1.156-1.394 W/m K and 2.833x10-7-8.814x10-7 m2/s. The values of specific heat, thermal conductivity and thermal diffusivity of unthawed cuttlefish were 0.453-1.111 cal/g C, 1.279-1.523 W/m K and2.891x10-7 -8.492x10-7 m2/s and those of thawed cuttlefish were 0.426-1.066 cal/g C, 1.244-1.493 W/m K and2.901x10-7-8.554x10-7 m2/s, respectively. The relationship between thermal properties of squid and cuttle fish and breeds, conditions of thawing and temperatures were found to be polynomial functions.