The attempts in this study were made to evaluate the variations in some needle characteristics of Pinus thunbergii between individual trees within population, between populations and between the hypothesized climatic districts. This species occurs naturally along 1:he southern seacoast of Korea penninsula having a relatively mild maritime climate. The followings are the summarized results. The coefficients of variation of the needle volume and needle serration density were generally higher than those of any other traits studied. The significant differences of variations of needle cross section form factor between individual trees within population at 1% level, except only the Young gwang population, were affirmed. In the case of the eastern seacoast district, where the three study populations are included, significances of variation differences were calculated, 5%r level at needle serration density and cross section area and 1% Level at needle volume. The very high significant difference of the variations of needle cross section form factor and needle longitudinal form factor were shown between population of the western seacoast district and 5% Level significance at needle volume in the southern seacoast district. The high significant differences between districts in respect to needle cross section form factor and cross section area were calculated. The Duncan`s multiple range test showed the dissimilarity of the said characteristics between the hypothesized climatic districts. Summing up the results obtained so far, individual tree and population variations were markedly noted statistically and these may be extended to the silvicultural technology.