In order to investigate the composition ratio and the emission rate of monoterpenes emitted from coniferous trees during summer, the enclosure chamber experiments were carried out for two tree species (Pinus densiflora and Pinus rigida). The major monoterpenes from the pine trees were $alpha$-pinene, $eta$-pinene, myrcene and $eta$-phellandrene. There was no difference of the composition ratio between two sites for P. densiflora, but the difference was observed for P. rigida. Clearly, the ratio of $eta$-pinene (26.1 %) for P. rigida was higher than that of $eta$-phellandrene (12%) at the Gumsung mountain site, but the ratio of $eta$-phellandrene (22.2%) was higher than that of $eta$-pinene (9.9%) at the Chiri mountain site. Particularly, the composition ratio of $eta$-phellandrene was higher than that of $eta$-pinene for P. densiflora, and the opposite trend was found for P. rigida at the Gumsung mountain site. The characteristics of the composition ratio between two species were similar at the Chiri mountain site. As a result of the emission rate measurements, it was observed that both sites did not show any significant $eta$ value (slope between emission rate and temperature) and ERs (Standard Emission rate at 3$0^{circ}C$) difference. However, the $eta$ value and ERs at the Chiri mountain site were slightly greater than those of Gumsung mountain site for both pine species. P. densiflora (1.703 and 1.971 $mu extrm{g}$C/gdw/hr) showed the higher monoterpene ERs than those of P. rigida (0.572 and 0.698 $mu extrm{g}$C/gdw/hr) at both sites.