Provided is a bath agent composition capable of satisfactorily exhibiting blood circulation promoting effect by generating carbon dioxide gas by comprising a carbonate and an organic acid therein and capable of satisfactorily exhibiting an additional effect by imparting high preservation stability. The bath agent composition comprises the following components: (A) a carbonate comprising 30 mass% or more of a dialkali metal carbonate (A1); (B) an organic acid; and (C) a CGRP response promoter.