Histological and chemical investigations on the cured Alaska pollack roe have been carried out with the purpose of explaining the low quality of its production. The results obtained are as follows. 1) Histological observations have been made on roe, with particular regard to the so-called "Mizuko" and "Gamuko". In the "Mizuko" a fairly amount of mature eggs were found, while the "Gamuko", however, contained eggs of an early developmental stage and of the degenerating stage. The normal product "Tarako" contained immature eggs corresponding to the yolk globular stage. 2) The difference in color of the roe before the process was probable due to the difference of the natural carotenoid content in both the oil globule and in the lipoprotein of egg. 3) It was ascertained that the "Murasakiko" was due to an occurrence of methemoglobin in roe.