By analyzing the relationship between the correlation coefficient of adjacent subsets and the quality of speckle patterns， a new speckle quality assessment parameter with a fixed range called mean adjacent zero mean normalized cross correlation is proposed， which can be used to assess the quality of single speckle pattern. By comparing the proposed mean adjacent zero mean normalized cross correlation， Shannon entropy and mean intensity gratitude， the stability of the proposed method is founded. The experiment results show that as the mean adjacent zero mean normalized cross correlation increases， the mean error and standard deviation in the displacement measurement decreases， and the quality of the simulated speckle pattern become better. When the maximum mean error of the speckle pattern in the displacement experiment is 0.01 pixel， mean adjacent zero mean normalized cross correlation is stable at around 0.90， while the other parameters vary greatly. These results prove that mean adjacent zero mean normalized cross correlation is effective and more suitable for quality assessment of single speckle pattern compared with other quality assessment parameters.