This study was performed to investigate the seasonal occurrence, developmental characteristics of each nymphal stages with different temperatures (20, 25, 30℃), longevity and fecundity of ussur brown katydid, Paratlanticus ussuriensis, damaging by outbreaks in the orchard areas of Bitan-ri, Yeongdong, Chungbuk. Paratlanticus ussuriensis occurred from late-March to late-August with peak of mid-May. Newly emerged nymphs appeared from March and do damaged fruit orchards with peak of mid-May when P. ussuriensis existed as 4th and 5th nymphal stages. P. ussuriensis adult occurred from early-June to mid-Aug. with peak of mid-July. Total density of P. ussuriensis was showed highest in mid-May. P. ussuriensis goes through nymphal stages to 7th nymph, the ovipositor began exposed to outside from the 4th instar and the body weight increased heavily from this stage and the wings were observed from 6th instar. Developmental period was longer as increased the nymphal stages. Sex ratio of collected insect was showed as 0.57; females more than males. As increased the temperature, developmental period was to be short. Preoviposition was also to be short as 5.0, 4.3, and 3.4 days at 20, 25, 30℃, respectively, and fecundity increased as 69.0, 87.1, and 104.3 at 20, 25, 30℃, respectively. Longevity of male and female at 25℃ was showed the longest with 35.7, and 32.9 days and showed the shortest with 30.1 and 28.1 days at 30℃, respectively. The difference of developmental period in male and female were showed longer in female without relation of temperature. The eggs laid were frequently distributed 3 to 4 cm from soil surface, and showed the behavior laying eggs intensively when early oviposition period.