Chlorophorus sp. (Coleoptera: Cerambycidae) has been a severe boring pest for Caragana spp. in Ningxia in recent years. Larvae of Chlorophorus sp. primarily damage the roots and branches of Caragana spp.. The authors analyzed damage characteristics and population dynamics of Chlorophorus sp. in this study. The results showed that the larvae and adults of Chlorophorus sp. mainly distributed in the stems at the height of 0～100cm, especially 0～20cm, and their numbers decreased from the base to the top. The larvae mainly damaged the plants of more than 4 years old, especially those in the age of 6～8 years. With the increase of plant diameter, the numbers of adult Chlorophorus sp. increased gradually, but the numbers of larvae increased first and decreased thereafter. The distribution of larvae in different periods changed greatly in the stems. The larvae moved from the base and top to the center, but they would move from the top to the base with gradual decreasing of temperature. The largest numbers of larvae were found in the stems of 0～20 cm, and this might be because the base provided a more suitable environment for overwintering.