This study was carried out to know bending process property of bentwood by treatment methods such as microwave and ammonia solution treatment. Bentwood processing was operated on bending-jig form with 60mm and 100mm radius of curvature (ROC). The species was used to Korean red pine (Pinus densiflora). No significant difference was shown in bentwood processing method on ROC. In treatment method, ammonia solution treatment for bentwood was better in dimensional stability and working ability than that of microwave treatment. However, bentwood stress was reduced with ammonia solution treatment. Color of bentwood surface appearance has a dark tendency in ammonia solution treatment. But it seems to beautiful effect of apparent annual ring is rising esthetically by ammonia solution treatment. To utilize wood as a exterior material for living amenity, it has to be closely examined from various angles including surface property, degree of swelling and shrinkage, drying state, retaining strength, durability, safety, and insect damage.