14C dating of 6 Japan cedars having the relative growing ages were made. On the basis of correlation analysis of our data to
a14C age data set, INTCAL of CALIB (Stuiver), the growing ages of these Japan cedars were estimated (BC 1090-2375). The atmospheric14C concentration (Δ14C) at their growing ages were obtained from the14C age data. The variation of Δ14C shows basically the same pattern with that of Europe or America (r=0.783).