The possibilities of an in vitro translation system, based on cell components of the hyperthermophilic archaeon, Thermococcus kodakaraensis, to utilize at a lower temperature range were examined. Green fluorescence protein (GFP) was used as the reporter protein. Through optimization of several experimental conditions, the yield of active GFP production at 40°C increased 5-fold. The optimized system was encapsulated in liposome made by passing through the oil/water interfaces. The prepared liposomes were incubated at 40°C for 90 min, and fluorescence was examined by laser confocal microscopy. A significant increase in average fluorescence intensity was observed in liposomes with GFP mRNA, indicating that the T. kodakaraensis in vitro translation system is applicable for protein production within giant liposomes. These artificial cell models should provide the means to reconstitute various cell functions from a synthetic biology approach.