Abstract: This paper deals with the floral components and soil nutrient dynamics and their relationship in Vatica mangachapoi forest on the tropical sandy beach .The results are : 1 The floral components of Vatica mangachapoi forest are different from that of other forest at the same climatic regions. 2 The plant species increase from 6 of which to 137 species ,especially 64 are tropical rain forest species, although the Simpson and Shannon-weiner indexes(species diversity indexes) are 2.19 and 2.34 respectively. Though the contents of the elements such as nitrogen, potassium, phosphorus etc. are extremely low, the contents of the soil nutrients increase appreciably along with the progressing of the forest community succession.

Key words: regional trial, testing-site discrimination ability, testing-site representativeness, relative least significant difference, experiment precision.