The chromatographic profiles of isoacceptor tRNA's for 9 amino acids from the loach embryos at two early developmental stages were compared by the method of chromatography on sepharose column in the decreasing gradient of ammonium sulphate concentration to elucidate the possible role of tRNA in the control of early embryogenesis processes. Certain differences both in the proportions of some isoacceptor peaks and their relative positions on the chromatographic profile were found for 8 aminoacyl tRNA. Methionyl-tRNA was represented by one constant peak.