In the second chapter, we consider a kind of Kolmogorov system.The sufficient conditions of nonexistence of the closed orbit and existence of the unique and stable limit cycle are obtained.

• 第二章讨论了一类Kolmogorov系统，得到了系统无闭轨的充分条件和存在唯一稳定极限环的条件，推广了颜向平，张存华等的结果。