To determine effects of temperatures and photoperiods on larval development of the mulberry longicorn beetle, Apriona germari, the larvae were reared at various rearing temperatures and under the various photoperiods on an artificial diet. The larval period of A. germari was extended as long as the temperature was lowered. Also the larval development in terms of length and weight of larvae was increased. However, survival rate during larval stage significantly decreased at 15$^{circ}C$ and $20^{circ}C$ than at $25^{circ}C$ and $30^{circ}C$. The results indicated that the favorable temperature for artificial diet rearing of A. germari fell at least above $25^{circ}C$ constantly. In photoperiod conditions, survival rate and larval development for A. germari were obviously most effective under a photoperiod of 14L:10B. As a result in artificial diet rearing of a. germari at $25^{circ}C$ and under a photoperiod of 14L:10D was mostly favorable in terms of larval development and period.