Abstract: In order to study the effect of floccule morphological characteristics on the collision and attachment between floccule and bubble,an image analysis system was designed. The video files of the contact motions between floccule and bubble were captured and the static frames with the position and morphological characteristics messages were ex- tracted. According to the particle sizes of floccules,the Image Pro Plus 6. 0 was used to divide the particle size frac- tions. The statistical method was used to calculate and analyze the collision and attachment probabilities between the floccule and bubble of each particle size fraction. The results showed that the collision efficiency increased with the floccule diameter,the attachment efficiency increased with the increase of floccule diameter,but decreased when the floccule diameter grew to 200 μm. The position extraction procedure of Matlab was used to obtain the location informa- tion of the floccule in the movement process,and calculate the floccule density based on the Stokes settlement princi- ple. The results showed that the floccule density had a regularity change with the floccule diameter,when the floccule diameter was 170 μm,the floccule density had the maximum value. The results showed that the diameter of floccule had a significant influence on the collision efficiency and the floccule density played a major role on the attachment efficiency. In addition,through the observation of the characteristics of the floccule movements,it was found that the con- tact point between the compactness structure floccule and the bubble was changeless,and the contact point between the loose structure floccule and the bubble was changeable. The loose structure floccule occurred a rotation,that meant the loose structure floccule was easy to fall off from the bubble and was hard to attach on bubble,therefore,the attach- ment efficiency was low.