Abstract:【Background】Common ragweed, Ambrosia artemisiifolia has successfully invaded Laibin, Guangxi, and it has impacted significantly local biodiversity, agricultural industry and resident′s health. Both Ophraella communa and Epiblema strenuana are important special natural enemies of A.artemisiifolia, and the two natural enemy species had suppressed the spread of A.artemisiifolia in Hunan Province, etc. 【Method】In order to explore the combined control effect of O.communa and E.strenuana on A.artemisiifolia, the two natural enemy species were released into the areas invaded by A.artemisiifolia in Laibin, Guangxi, on May 24, 2009 (densities of the two natural enemy species were 1170 individuals·hm-2). 【Result】The mortality of A.artemisiifolia plants was up to 98% on August 29, 2009, and the two natural enemy species spread to the adjacent areas invaded by A.artemisiifolia rapidly. The effect of the two natural enemy species on A.artemisiifolia was 50%~60% in the spread areas. 【Conclusion and significance】The two natural enemy species had a significant control effect on A.artemisiifolia, it′s suggested that biological control technique of A.artemisiifolia with O.communa and E.strenuana can be applied in Guangxi Province.