Abstract: A large area of limestone mountain is occupied in southw estern Guangxi, in which there is a special limestone seasonal rain forest differing from seasonal rain forest in acid soil mountain formed by sandstone, shale or granite.The paper is mainly engaged in research of its classification and geographical distributional law.Apreliminary classification system is described as follows:1 Limestone seasonal rain forest dominated by Tiliaceae and other families 1.1 Formation dominated by Burretiodendron hsienmu and Cephalomappa sinensis 1.2 Formation dominated by Burretiodendron hsienmu and Garcinia paucinervis 1.3 Formation dominated by Burretiodendron hsienmu, Canthium dicoccum and Boniodendron minor 1.4 Formation dominated by Burretiodendron hsienmu and Cinnamomum saxatile 1.5 Formation dominated by Burretiodendron hsienmu and Miliusa glochidioides 1.6 Formation dominated by Burretiodendron hsienmu and Cyclobalanopsis glauca 1.7 Formation dominated by single species -Burretiodendron hsienmu 2 Limestone seasonal rain forest dominated by Euphorbiaceae 2.1 Cephalomappa sinensis Formation 2.2 Deutzianthus tonkinensis Formation 2.3 Bischofia javanica Formation 2.4 Cleistanthus saichikii Formation 3 Limestone seasonal rain forest dominated by Leguminosae 3.1 Lysidice rhodostegia Formation 3.2 Saraca chinensis Formation 4 Limestone seasonal rain forest dominated by Ulmaceae and other families 4.1 Formation dominated by Giro nniera subaequalis and Aphanamixis grandifolia 5 Limestone seasonal rain forest dominated by My risticaceae 5.1 Horsfieldia hainanensis Formation 6 Limestone seasonal rain forest dominated by Dipterocarpaceae 6.1 Shorea chinensis Formation

Key words: Limestone seasonal rain forest, Community classification, Formation, Association, Vegetation