An atomic decomposition based power quality（PQ） disturbance analyzing method is introduced. The method applies dictionary of Gabor atoms and matching pursuit algorithm to extract the atomic components iteratively from the PQ disturbance signals. The extracted Gabor atomic components are translated to damped sinusoidal components and the parametrical and analytical representation of atomic components for the PQ disturbances is obtained. In order to extract the features more effectively， the ending condition of decomposing iteration is determined by a threshold referred to the initial residual energy. As a result， the proposed method can precisely extract the starting and ending moment of disturbances as well as their magnitudes， frequencies and other features， suitable for analyzing PQ disturbances including static， transient and multiple ones. Examples indicate the effectiveness of the proposed method.