Abstract: In order to determine occurrence regulation and of Janus piri in Jingtai, Gansu Province, the damage and life history of J. Piri were investigated by the five point sampling from 2011 to 2012 with yellow trap board. The results of periodical sampling and trapped adults monitoring showed that J. piri occurred one generation every year and mainly damaged fresh treetop. Pupa overwintered in the damaged branches. Different varieties and trees at different ages had different damage degrees. The adults began to damage the pear shoots when it was sunshiny and the temperature was above 21℃ at 9:00 am from the end of April to the beginning of May, and the damage period was 4~6 days. The results indicated that it was the key period for controlling the adults of J. piri when adults occurred at the peak and got out of the shoots.