在越南同奈天然文化自然保护区设置150个样地,运用生态学理论,采用Logitic模型和生态学统计方法,分析表层土壤湿度和pH值对胖大海幼树幼苗更新出现频率的影响.结果表明,胖大海幼树幼苗在SL1、SL2和SL3三个阶段的天然更新出现频率均与各林分胖大海的优势度、表层土壤湿度和pH值有密切关系.适合胖大海幼树幼苗更新的表层土壤湿度:SL1阶段是57.7%~78.8%,最适度是68.2%;SL2阶段是64.8%~80.7%,最适度是72.8%;SL3阶段是65%~80%,最适度是73.3%.适合胖大海幼树幼苗更新的表层土壤pH值:SL1阶段是3.5~5.7,最适度是4.6;SL2阶段是4.4~5.9,最适度是5.1;SL3阶段是5.0~6.5,最适度是5.5.胖大海的丰富度变化受表层土壤湿度和pH值2个因素的影响,其关系能够用Logit Gauss模型来表征.表层土壤湿度和pH值受森林类型影响,胖大海高优势度林分或者高稳定性林分具有更适合胖大海幼树幼苗天然更新的环境. A total of 150 plots were set up in Dong Nai Natural Cultural Reserve in Vietnam. The ecological effects of the surface soil moisture and pH value on the regeneration frequency of sapling seedlings were analyzed by using the ecological theory, Logitic model and ecological statistics. , The frequency of natural renewal of juvenile P. sativa seedlings in SL1, SL2 and SL3 stages was closely related to the dominant degree, surface soil moisture and pH value of P. chinensis seedlings, The soil moisture was 57.7% -78.8% in the SL1 stage and 68.2% in the optimum stage, with the optimum stage being 64.8% -80.7% in the SL2 stage and 72.8% in the optimal stage and 65% -80% in the SL3 stage and 73.3% in the SL3 stage. The surface soil pH values ​​of the saplings of saplings were updated from 3.5 to 5.7 for the SL1 and 4.6 for the SL1 and 4.4 to 5.9 for the SL2 and 5.0 to 6.5 for the SL3 and 5.5 for the SL3 The change of richness is affected by two factors of surface soil moisture and pH value, and the relationship can be characterized by Logit Gauss model. The surface soil moisture and pH value are influenced by the forest type. The forest of high and low water level or high-stability forest Have more suitable for the natural regeneration of young saplings sapling environment.