The authors reared the ash-gray leaf bug, Piesma sp. B in the growth cabinet controlled as temperature groups of 15, 20, 25, 30, ,35, 40$^{circ}C$ under condition of photoperiod 16L: 8D, light intensity 510${pm}$2401ux, relative humidity 65${pm}$3%, and analyzed the effects of temperature on the development of the insect. The results are summarized as follows: 1. There are highly significant differences between the developmental periods for the temperature groups, and between the developmental periods for the developmental stages. 2. The egg in the temperature of 15 and 40$^{circ}C$ was hatched, but the ecdysis was impossible. The thermal threshold was 3.4$^{circ}C$ and the upper lethal temperature 47 33$^{circ}C$. 3. The total developmental periods of egg to adult in the temperature of 20, 25, 30 and ,35$^{circ}C$ are 68.73, 37.86, 38.16 and 31.68 days, respectively. That is, the developmental period was decreased, as the temperature was increased. 4. In the developmental period for the developmental stages, the developmental period of egg stage was longer than that of any stage except the fourth and the fifth larva stage. And there was not significant differences between the developmental periods for the other developmental stages. 5. In the developmental relied for the temperature, that of 20$^{circ}C$ was longer than that of 25, 30 and 35$^{circ}C$. But there was not significant differences between the developmental periods for the other temperature group. 6. The rate of hatch at 20$^{circ}C$ is the greatest value as 98%, and the rates of 25, 30 and 35$^{circ}C$ are 97, 93 and 97% respectively There was not significant differences between the rate of hatch for the temperature group. 7. The mortality in the temperature of 35$^{circ}C$ is the greatest value as 93%, and those of 30, 25 and 20$^{circ}C$ are 85, 82 and 68%, respectively That is, the mortality was increased, as the temperature was increased. 8. There was not significant differences between the developmental period of female and male.