[Objectives]  Agrilus fleischeri Obenberger is a newly emerged wood borer of poplar trees, which has been becoming a destructive pest in Liaoning Province, northeast China recently. To develop effective management strategies of this beetle, and provide suggestions for reasonable matching tree species in reforestation process, we studied the damage of exotic species Populus nigra var. italica and native species P. davidiana. [Methods]  Two pure stands of P. nigra var. italica and P. davidiana were set up as field investigation sites. Twenty P. nigra var. italica and twenty P. davidiana trees were selected randomly and girdled in early spring of 2013 and 2014 respectively to attract A. fleischeri female adults for oviposition. Natural and stressed infestation rates of two species of poplar trees were surveyed in the field. Population densities, mortality and lethal factors of the beetle were investigated by dissecting infested host trees. [Results]  Results indicated that the natural infested percentages of P. nigra var. italica and P. davidiana were 11.76% and 0 with a significant difference, while 90% artificially stressed P. nigra var. italica and 65% stressed P. davidiana were infested by A. fleischeri after girdling. The average population densities of the pest were 61.95 larvae per tree on P. nigra var. italica and 34.89 larvae per tree on P. davidiana. Egg hatch rate on P. nigra var. italica (91.78%) was significantly higher than that on P. davidiana (77.61%). Larvae of A. fleischeri were mainly found in galleries with an average 48.68 cm in length on P. nigra var. italica and those were 29.59 cm on P. davidiana. The differences of pupal chambers on the two species of poplar trees were not significant in length, width and depth. Moreover, a vertical distribution model illustration of exit holes of A. fleischeri on the trunk was established, which revealed that exit holes mainly distributed in 1-6 m on P. nigra var. italica and 1-3 m on P. davidiana above ground. Difference of niche width of A. fleischeri larvae and their natural enemies also accounted for the different damage degrees. Niche width of A. fleischeri larvae were 0.53 and 0.32 on P. nigra var. italica and P. davidiana respectively. [Conclusion]  Exotic poplar species P. nigra var. italica is more vulnerable than native poplar P. davidiana. Our findings can provide information and scientific support for the management of the pest and rational reforestation in practice.