Abstract: It was proved in the previous report that the Chinese made ceramic tools may be used to turn the carbon steel of mediate strength and the tool life may be sufficient long. But the surface quality obtained by using this new kind of non-metallic tool material should also be studied. In this report, the influence of several main cutting parameters, such as cutting time (I. e. tool wear), cutting speed and feed upon the surface quality obtained by using ceramic tools is described. The surface quality, in itself, implies the surface finish, effect of strain hardening, transformation of surface metallography and also machining accuracy. The material to be machined is medium carbon steel (No. 45). All results obtained by using ceramic tools are systematically compared with that obtained by using Soviet made cemented carbide tools (T10K5) in the same cutting conditions. It is found that the surface finish obtained by using ceramic tools is almost in all cases higher than that obtained by using cemented carbide tool (T15k6). And it is very interesting to note that the surface finish curves which correspond to ceramic tools (Fig, 6 B and C) are more or less horizontal, in other words, the surface finish obtained by using ceramic tools is independent of cutting time, hence of tool wear (within some limit). While the curve which corresponds to T15k6 tool (Fig. 6A) is inclined upward straightly as a rule. The authors believe, this is probably due to the higher heat influence during cutting with ceramic tools (since the heat conductivity of ceramics is much lower than that of carbides), hence the "built up edge" is reduced and the surface finish is improved. In addition to this, the so-called "smoothing effect" of ceramics may be higher than that of carbides.Nevertheless, the machining accuracy obtained by using ceramic tools is considerably lower than that obtained by using T15k6 tools, because the tool wear of the former is considerably higher than that of the latter. In regard to strain hardening, the result indicates that either the depth of hardening or the surface microhardness produced by ceramic tools is larger than that produced by carbide tools. Further more, when the cutting time of ceramic tool is sufficient long or when its cutting speed is sufficient high, in the extreme surface layer (its thickness is smaller than 20 microns) of the steel bar occurs some metallographic transformation. Under these conditions, because the surface temperature of the steel bar may be sufficient high to exceed the critical point of the material cut, therefore occurs a to r transformation. And then, this surface layer is immediately cooled by the inner portion of the bar, hence in the surface metallographs (Fig. 8c and Fig. 13) occurs sorbitelike structure. The authors believe that the heat influence during cutting with ceramic tools is worthy enough to be thoroughly studied in the next step of research.