Abstract: Pinus yunnanensis var. tenuifolia Formation is extensively distributed in the hills and mountains with an altitude from 300-1600m. along the lower Nanpanjiang river. 11 plant associations have been found in this area. They are described as follows:1. Pinus yunnanensis var. tenuifolia-Quercus Yuii-Wend-landia uvarifolia subsp. dunniana-Microstegium vagans+Pogonatherum paniceum Association. 2. Pinus yunnanensis var. tenuifolia-Quercus variabilis-Quercus yuii-Miscanthus floridulus+Pogonathernm paniceumAssociation. 3. Pinus yunnanensis var. tenuifolia-Quercus fabri-Vacci-nium sprengelii-Arundinela nepalensis+Pogonatherum pani-ceum Association. 4. Pinus yunnanensis var. tenuifolia-Schima wallichii-Rhodomyrtus tomentosa-Dicranopteris dichotoma Association. 5. Pinus yunnanensis var. tenuifolia-Wendlandia uvarifo-lia subsp. dunniana-Arundinella nepalensis+Pogonatherum pa-niceum Association 6. Pinus yunnanensis var. tenuifolia-Phyllanthus emblica-Eulaliopsis binnata+Heteropogon contortus Association. 7. Pinus yunnanensis var. tenuifolia-Vaccinium sprengelii-Cymbopogon caesius+Eulalia speciosa Association. 8. Pinus yunnanensis var. tenuifolia-Phyllanthus emblica-Eulalia quadrinervis Association. 9. Pinus yunnanensis var. tenuifolia-Arundinella mepalenisis+Cymbopogon caesius Association. 10. Pinus yunnanensis var. tenuifolia-Quercus yuii-Arun-dinella nepalensis Association. 11. Pinus yunnanensis var. tenuifolia-Adiantum flabellula-tum Association.