In this paper, cut marks on the long bones of class Ⅱ sized animals in the Ma’anshann site are studied. Based on the location and frequencies of the long bone cut marks, the distribution characteristics are analyzed as follows: (1) cut mark frequencies in the lower layer (LL) are much higher than those of the upper; (2) in the LL cut mark frequency of the upper limbs is the highest, and that of the middle and lower limbs is lower and the lowest; (3) In the upper layer (UL) the cut mark frequency, does not spread as orderly as in the LL. The data are compared to those of the experiment and it is demonstrated that values of the LL all fall into the experimental 95% confidence intervals, and the cut mark frequencies of the upper, middle and lower limbs coincide with those of the experiment; while the values of the UL are much lower, of which, those of the humerus, femur and radius are out of the intervals, and the frequencies of the upper, middle and lower limbs are far more different from those of the experiment. It implies that the earlier hominids (of the LL) defleshed the limbs of the class Ⅱ sized animals with stone tools more completely than the later hominids. With the evidence of burning marks, it is suggested that the difference on the roasting behaviors derived the cut mark difference of the Ma’anshan UL and LL. In this paper, cut marks on the long bones of class Ⅱ sized animals in the Ma’anshann site are studied. Based on the location and frequencies of the long bone cut marks, the distribution characteristics are analyzed as follows: (1) cut mark frequencies in the lower layer (LL) are much higher than those of the upper; (2) in the LL cut mark frequency of the upper limbs is the highest, and that of the middle and lower limbs is lower and the lowest; (3) In the upper layer (UL) the cut mark frequency, does not spread as orderly as in the LL. The data are compared to those of the experiment and it is demonstrated that values ​​of the LL all fall into the experimental 95% confidence intervals , and the cut mark frequencies of the upper, middle and lower limbs coincide with those of the experiment; while the values ​​of the UL are much lower, of which, those of the humerus, femur and radius are out of the intervals, and the frequencies of the upper, middle and lower limbs are far more different f rom those of the experiment. It implies that the earlier hominids (of the LL) defleshed the limbs of the class Ⅱ sized animals with stone tools more completely than the later hominids. With the evidence of burning marks, it is suggested that the difference on the roasting behaviors derived the cut mark difference of the Ma’anshan UL and LL.