Elemental analyses, using wave-length dispersive X-ray spectrometers, on the otolith of 1-year-old red sea bream, Pagrus major, from five areas in the Tsushima Warm Current showed the two fluctuation patterns of strontium Lα X-ray counts. The strontium X-ray counts in the otolith sections from the area off Nagasaki Prefecture were approximately constant while some slight fluctuations on the edge were found in a few otoliths. However, the counts in the otoliths from the area off Akita Prefecture distinctively increased with otolith growth and decreased after peaks were shown. Coefficients of variation of strontium X-ray counts of individuals were 5.84~8.53% for fish from the area off Nagasaki Prefecture and 6.44~13.40% for fish from the area off Akita Prefecture.