Abstract:Seedlings of Acacia auriculaeformis, Eucalyptus urophylla, and Schima superba were tr ansplanted in canopy gaps and under secondary broadleaved forest, Pinus m assoniana forest, Acacia auriculaeformis forest, a nd Eucalyptus robusta forest on Nan'ao Island, Guangdong Provin ce. Leaf area index (LAI), transmittance, and seedling height were measured. Res ults indicated that LAI was greater under forests than in gaps, and the transmit tance was much higher in gaps. Both LAI and transmittance changed with the seasons． Seedlings ofthe three species grew fasteringapsthan un derforests．Seedling height of Acacia and Eucalyptus in gaps increased more obviously than that of Schima， showing ecological response of species to canopy gap condition.