In order to determine the optimal storage conditions of Capsosiphon fulvescens (maesaengi), 2 types of wash solutions (distilled water and seawater) and storage temperatures (-20 and $-80^{circ}C$) were evaluated for the effectiveness of microbial growth inhibition and the changes of texture, color, and proximate composition. Thawed samples that had been washed with seawater and stored at $-20^{circ}C$ for 50 days showed a 1.1-fold increase in hardness compared to the initial hardness of the sample ($1.9{ imes}10^5;dyne/cm^2$). There was no change in moisture, ash, or crude lipid during storage at -20 and $-80^{circ}C$ for 60 days, while there was a $1{pm}0.2%$ decrease in crude protein content for the control during storage at both -20 and $-80^{circ}C$ for 60 days. In conclusion, the recommended optimal storage conditions for retaining the quality of C. fulvescens are: temperatures at or below $-20^{circ}C$ and washings with either distilled water or seawater for inhibiting microbial growth, temperatures at or below $-20^{circ}C$ and a washing with seawater to prevent reductions in hardness, and a temperature of $-80^{circ}C$ and washings with either distilled water or seawater to protect against color changes.