Abstract: There is larger area of limestone mountain in Guangxi in which occurs a special limestone mixed evergreen and deciduous broadleaf forest. It often forms mosaic distribution with together evergreen broadleaf forest in acid soil area. This paper mainly deals with its classification and geographical distributional law. A preliminary classification system has been set up in Guangxi. They are discribed as follows:1. Limestone mixed evergreen and deciduous broadleaf forest dominated by Fagaceae and other families 1.1 Limestone mixed evergreen and deciduous broadleaf forest dominated by Cyclobalanopsis glauca and other deciduous broadleaf trees. 1.1.1 Mixed forest dominated by Cyclobalanopsis glauca and Bridelia fordii 1.1.2 Mixed forest dominated by Cyclobalanopsis glauca and Choerospondias axillaris. 1.1.3 Mixed forest dominated by Cyclobalanopsis glauca and Aphanamix grandifolia. 1.1.4 Mixed forest dominated by Cyclobalanopsis glauca and Celtis biondii. 1.1.5 Mixed forest dominated by Cyclobalanopsis glauca and Platycarya strobilacea. 1.1.6 Mixed forest dominated by Cyclobalanopsis glauca and Platycarya longipes. 1.1.7 Mixed forest dominated by Cyclobalanopsis glauca and Sapium rotundifolium. 1.1.8 Mixed forest dominated by Cyclobalanopsis glauca and Pistacia chinensis. 1.1.9 Mixed forest dominated by Cyclobalanopsis glauca and Pteroceltis tatarinowii. 1.1.10 Mixed forest dominated by Cyclobalanopsis glauca、Wrightia pubescens and Boniodendron minor. 1.1.11 Mixed forest dominated by Cyclobalanopsis glauca、Lysidice rhodostegia and Adenanthera pavonina. 1.1.12 Mixed forest dominated by Cyclobalanopsis glauca、Garcinia paucinervis and Radermachera sinica. 1.2 Limestone mixed evergreen and deciduous broadleaf forest dominated by Cyclobalanopsis glaucoides and other deciduous trees. 1.2.1 Mixed forest dominated by Cyclobalanopsis glaucoides and Platycarya glandulosa. 1.3 Limestone mixed evergreen and deciduous broadleaf forest dominated by Castanopsis formosana and other deciduous trees 1.3.1 Mixed forest dominated by Castanopsis formosana and Radermachera sinica. 1.4 Limestone mixed evergreen and deciduous broadleaf forest dominated by Castanopsis hainanensis and other deciduous trees 1.4.1 Mixed forest dominated by Castanopsis hainanensis and Sapium rotundifolium. 2. Limestone mixed evergreen and deciduous broadleaf forest dominated by Lauraceae and other families. 2.1 Limestone mixed evergreen and decidecous broadleaf forest dominated by Machilus pauhoi and other deciduous trees. 2.1.1 Mixed forest dominated by Machilus pauhoi and Itoa orientalis. 2.1.2 Mixed forest dominated by Machilus pauhoi and Cladrastis platyphylla. 2.2 Limestone mixed evergreen and deciduous broadleaf forest dominated by Machilus kwangtungensis and other deciduous trees. 2.2.1 Mixed forest dominated by Machilus kwangtungensis and Swida parvifolia. 2.3 Limestone mixed evergreen and deciduous broadleaf forest dominated by Beilschmiedia kweichowensis and other deciduous trees. 2.3.1 Mixed forest dominated by Beilschmiedia kweichowensis and Bridelia fordii. 3. Limestone mixed evergreen and deciduous broadleaf forest dominated by Rubiaceae and Sapindaceae. 3.1 Mixed forest dominated by Canthium dicoccum and Boniodendron minor. 3.2 Mixed forest dominated by Boniodendron minor and Mastichodendron wightianum. 4 Limestone mixed evergreen and deciduous broadleaf forest dominated by Juglandaceae and other families. 4.1 Limestone mixed evergreen and deciduous broadleaf forest dominated by Engelhardtia chrysolepis and other deciduous trees. 4.1.1 Mixed forest dominated by Engelhardtia chrysolepis and Choerospondias axillaris. 4.1.2 Mixed forest dominated by Engelhardtia chrysolepis and Celtis sinensis. 5 Limestone mixed evergreen and deciduous broadleaf forest dominated by Magnoliaceae and other families 5.1 Mixed forest dominated by Kmeria septentrionalis and Styrax suberifolia.

Key words: Limestone mixed evergreen broadleaf forest, Formation, Formation group, Subformation group, Vegetation