Abstract: The Kengnan site is located at Xichuan County, Henan Province. From this site, a series of layers from Paleolithic to early Neolithic ages with abundant artifacts are found including lithics, pottery, which show the importance of this site in the area of the Hanjiang river. In this paper, starch grains extracted from the surface of 35 stone artifacts from two early Neolithic layers of the Kengnan site are analyzed. Among them, 150 starch grains have been found on the surface of 17 artifacts. The starch grains are identified as seeds of Paniceae (including Panicum miliaceum and Panicum bisulcatum or Setaria italica) , Coix sp., stems from Triticeae dumor and root and tuber plants, all of which indicate the utilization of plant resources by the ancient inhabitants. A substantial increase of the quantity and typology of starch grains is found from the second to third layer. This observation may be related to three important factors. First, it may be related to the different buried ages between the two layers since artifacts can be influenced by climate and other forces of nature. Second, it may be related to increasing temperature in the early stages of the Holocene, as well as increasing the kinds of plants from which ancient people acquired. Third, such difference can also be influenced by the ability of absorption caused by different hardness, cavities and pores of stones, and the different functions of these stone artifacts. The abundant starch grains from Gramineae found on chopping tools provide us with a new vision on the functions of stone tools

Key words: Kengnan; Early Neolithic; Stone artifacts; Starch grains; Plant