Abstract: According to the principal theory of Keeley(1980), the microwear research of this paper(one part of a master degree thesis of the author's*) consists of analysis on experimentally used tools and a blind test.
In the use experiments of 40 flint tools, 22 use methods were adopted on 77 used edges inall. Worked materials include wood(dry, damp), fresh meat, fish, hide, and bone; motion ac-tivities are scraping, whitling, cutting, sawing, chopping, wedging, piercing, drilling and car-ving, Through the leading technical method of scanning electron microscope(SEM), distingui-shable characteristics are identified by analyzing microwear traces produced from different use methods. It comes to some valuable results and personal understanding:
1. Using SEM for analyzing microwear on stone artifacts has its advantages, even though itexists limitations as compared with optical microscope.
2. Crystal damage" was discovered on used flint tools for scraping wood. Partial damageof the crystal was observed in a groove under the SEM. The position of the crystal damage de-pends on the mechanics resource.
3. Patterns of edge damage are possibly influenced by concrete shape of the used edge invarying degrees. For instance, in the experiments of scraping wood, on the uncontact surface of a straight edge--hollow rectangles partitioned by vertical ridges were easily observed transverse fractures occur tier upon tier closely abovt the are scars. For a cónvex edge, sunken trapezium partitioned by vertical ridges with semilunar scars.
Moreover, scar patuerns have relation to using activities. Whittling wood can produce ashell shaped depression.
4. Similar to polishes and striations, texture and micropits shown on the steep edge can re-flect some characters of different motions or worked materials. On the micro- surface of an cdgefor sawing wood, scattered texture, deeply micropits elongate along with the edge. and the rimsof the micropits can indicate the direction of using. By scraping wood, dense texture, elongated micropits with narrow ends and obviously depressed in the center of itself could also be seen in the texture, but cannot be clearly separated from the general micro-surface.For cutting fat or scraping fresh hide, textures on the edge appear very fine and smoothly.
5. On the contact surface there are clearly radial polish lines developing in a short breadth after the edge was used for scraping wood, Polishes from whittling activity distribute longer,narrower more than scraping but similar radial character.
6. Working on hard materials, such as wedging wood or bone, there is transverse polish tapein a certain distance away from the edge. It might be a typical feature to distinguish this activity.
In order to test the level of controlling microwear's appearance of the analyst, 9 flint samples (8 had been used among them) were chosen in the blind test.
Use was correctly discernedin 100% of the cases; motion/activity in 78% of cases; and worked material in 70% of casesIn the study of microwear on stone tools, exper imental planning provides crucial links forrealizing the value of the experiment. Blind tests are advisable on researching archaeological artifacts.
This article also has a brief introduction about the history of microwear studies and givesfurther prospects in this field. When putting forth efforts to research purely direct use wear, we shouldn't neglect indirect use microwear and microwear traces from other sources. Microwear analysis is not only useful for analyzing the functions of stone artifacts, but also has other importance, for example, grasping traces could help us know the hand using habits of ancient human beings.

Key words: Stone artifacts; Scanning electron microscope; Microwear; Blind test