Abstract:In order to understand the natural regeneration mechanism of the P. thunbergii coastal shelter forest, we established 60 plots (10 m×10 m) on six transects distributed throughout two stands in Yantai region of Shandong province, China. Using fitting model and multiple techniues, the effects of forest vertical structural indicators (crown index, proportion of small and large trees) and density indicators (basal area, canopy coverage and shrub coverage) on natural regeneration of P. thunbergii coastal shelter forest were studied. The results indicated that a parabolic model could delineate the relationship between crown index and number of juveniles well. The highest number of juveniles occurred when crown index (CI) ranged from 5 to 6. The positive correlation between the number of juveniles and the proportion of large trees was strong, while that between the number of juveniles and the proportion of small trees was not significant. As long as the density indicators, the number of juveniles was positively related to canopy coverage, but negatively to shrub coverage and not apparently to basal area. Regression analysis indicated that the variation of juvenile density was determined by the combined effects of vertical structural indicator (e.g. CI) and density indicators (canopy coverage, shrub coverage). A full understanding of those regeneration rules is a prerequisite for sustainable management of P. thunbergii coastal shelter forest.