Abstract:This paper reviewed the theory of forest cycle, the concepts of natural disturbance, characteristics of forest gaps and the spatial/temporal patterns of gap disturbance. Disturbane is a driving force of forest growth cycle, and gap phase, caused by disturbance, is the initiating point of the cycle. The following are very important parameters in the studies of gap characteristics: gap size, gap age, manners of formation and gap makers. Although gap disturbance regimes are different in different forest communities, the average annual disturbance frequency is about 1% in most forest types. For different forest types, the preportions of small scale and large scale disturbances are different. The combination of small scale gap disturbance and large scale catastrophic disturbance in different conditions forms the basis of landscape pattern.