The leafy vegetable Hirosimana (Brassica pekinensis var. Hiroshimana) of Brassicaceae is salted and consumed in pickled form. The main flavor components of Hiroshimanazuke (salted Hirshimana) are isothiocyanetes (ITCs), the products of enzymatic conversion by myrosinase. ITCs are highly reactive and unstable compounds, and their formation and decomposition rate are greatly affected by temperature. The decomposition of flavor components in Hiroshimanazuke was investigated during the drying process. The results indicated that temperature was an important factor for the decomposition of flavor in Hiroshimanazuke during the drying process. Low temperatures were necessary to suppress the formation and decomposition of ITCs in Hiroshimanazuke. Thus, it would be quite difficult to preserve the flavor of Hiroshimanazuke without freeze-drying.