In this study, rolled Mg-Ca alloys were processed by high-temperature pre-annealing at 500℃ and subsequent warm rolling at 200℃. The rolled alloys processed by repetition of the above rolling procedure were finally annealed at 350℃. This process was effective rolling procedure for suppression of basal texture formation of Mg-Mn and Mg-Ce alloys. The rolled Mg-0.1Ca alloy exhibited a significantly increased Erichsen value of 7.1, which was much larger value compared with commercial Mg alloys. On the other hand, excessive calcium addition more than 0.3 mass% deteriorated room temperature formability. Basal texture intensity of Mg-Ca alloys had much smaller value, when calcium concentration was set more than 0.1 mass%, indicating that the suppression of basal texture formation mainly contributed to the enhanced stretch formability of Mg-0.1Ca alloy. The deteriorated formability of Mg-0.3Ca alloy was attributed to the formation of coarse precipitates in the alloy. Retardation of dynamic recrystallization during warm rolling was suggested to be one of the reason for suppression of strong basal texture formation for Mg-Ca alloy, when calcium concentration was set to more than 0.1 mass%. The internal friction of the Mg-0.1Ca alloy was found to be almost the same as that of pure magnesium at certain strain amplitude.