In the previous report, in the salted brown seaweed Laminaria japonica, two green pigments, which were assumed to be allomerized products of chlorophyll (Chl.)a, were detected. Succeedingly, the stereoisomers of allomerized products from Chl.a were prepared, and compared with two pigments isolated from the ethanol extract from the salted seaweed in HPLC, NMR and CD methods. The results indicated that the two pigments were identified as 10-hydroxy-Chl.a and its epimer, 10-hydroxy Chl.a', respectively.