Abstract: In order to study the biological features of unearthed rhythm and phototaxis of Curculio davidi Fairmaire, observadions were conducted on the amount and progress of unearthed adults and their phototaxis ratio to reflective and direct light sources. The results showed that the adult emerged from late May to late June, lasting for 30 days, with the initially fast pace of and then gradually pace slow and the maximum period was from late May to early June. The Curculio davidi adults were most sensitive to reflective purple and black light, and with a percentage of 56.11 and 55.00 respectively. Due to various factors in the field, the trapping and killing effect was not so efficient and the daily average trapping amount was 1.9 and 2.3 respectively. And the study proved the characteristics of weak phototaxis of adults. The unearthed period was a very crucial stage of preventing and controling the harm of Curculio davidi Fairmaire and the risks of its plague. So this stage should be taken seriously.