Pollen analysis of 19 samples from 4 locationsin in the P'u-li Basin in Nantou Country , ROC. Was carried out during 1972-3. A total of 5,000 fossil palynomorphs were observed and identified. Based on the different pollen assemblages, the pollen diagram has been classified into zones A and B. Zone B is divided into subzones B1, B2 and B3. Zone A, with samples from the surface layer of each site, was characterized by subtropical and temperate elements, such as Pinaceae, Betulaceae, Magnoliaceae, Euphorbiaceae, Rubiaceae, Cyperaceae, Convolvulaceae and Gramineae. Zone B, was found from samples in the deeper layers of the sites. Most components of subzone B1 and B3 were subtropical waste land elements, namely Plantago, Carex, Cyperus, Gramineae, and genera of Convolvulaceae. Pollen assemblages of subzone B2 are the same as those of zone A. Indicator pollen grains for reforestation are those of Cryptomeria, Cunninghamia, and Punus, and for crop cultivation are assemblages of Plantago, Ipomoea, Cyperus, Carex, Gramineae and Chenopodium. According to radiocarbon dating the initial deforestation of the area occurred between 5,000 to 15,900 B.P. before the beginning of zone B. Evidence for cultivation are shown by the appearance of cereal pollen grains and waste land elements from subzone B3 by at least 3,000 B.P. The evidences of pottery and lithic artifacts indicated that the Neolithic peoples of the Lunshanoid culture of southwest Taiwan and southeast China arrived to this area before 2381 B. P.