The stability of three major pigments in lavers, namely chlorophylls, carotenoids, and phy-cobilins, during processing and storage was studied. The results of the pigment retention in fresh lavers during storage at low temperatures, of heat lability during heat treatment, and of the pigment loss during storage are summarized as follows: 1. The contents of chlorophyll a, xanthophyll (lutein+zeaxanthin), and carotene ($\alpha-+\beta-carotene$) averaged 1,525, 627, and $409{\mu}g/g$ of dry samples respectively The comparative composition of four carotenoids, lutein, $\beta-carotene$, zeaxanthin, and $\alpha-carotene$, was 35.9, 33.7, 12.2, and $5.8\%$ respectively. 2. In storage of fresh lavers at room ternperature ($20-25^{\circ}C$), 2 to $5^{\circ}C$, and $-15^{\circ}C$, the pigments generally were retained more at 2 to $5^{\circ}C$ than others while carotene only showed more retention at $-15^{\circ}C$ than at 2 to $5^{\circ}C$. Phycocyanin tended to decrease more rapidly than phyco-erythrin at low temperatures. 3. In regard to heat treatment of both dried and wet materials at 40, 60, 80, $100^{\circ}C$ respectively, the pigments were more stable at lower temperatures than at higher temperatures in both cases of materials. Carotenoids were retained more in wet materials than in the sun dried. Xanthophylls showed higher heat stability than carotenes. Phycoerythrin was considered more heat labile than phycocyanin, particularly at higher temperatures. 4. In storage of heat treated lavers for 50 days at room temperature, the retention of pigments appeared differently in accordance with the temperatures of treatment The materials treated at $60^{\circ}C$ showed better relention of pigments than those treated at the other temperatures. Degradation rate of xanthopllylls, carotenes, and phycobilins was decreased in the materials treated at higher temperatures, showing a tendency of great pigment retention even for a long period storage. Chlorophyll il was retained more in sun dried materials whereas xanthophyll and carotene were retained more in the wet. 5. In order to maintain a higher pigment stability during storage, the materials must be treated at $60^{\circ}C$ in a dryer with rapid ventilation until the moisture level reaches about $6.0\%$. In case of treatment at a higher temperature than $60^{\circ}C$, they must be treated for a short period of time to minimize pigment degradation by heat. 6. The lavers treated with the solutions of pH around 7.8 showed a higher retention of chlorophyll a. When treated with the solutions of algal extracts such as agar and alginic acid, uniform layer of laver sheets and better surface gloss of dried layers were obtained.