Abstract: The effects of deflaking on the drainability, fiber morphology as well as the ash and silica contents of rice straw alkali-oxygen pulp were investigated. The results indicated that the beating degree of the pulp without non-fibrous cells fell around 10°SR. Deflaking played a negative role in the drainability of the pulp. However, the development trend of the beating degree originated from deflaking depended marginally on non-fibrous cells, but greatly on pulp fibers. This resulted from the fibrous deformation sensitive to deflaking. On the other hand, it was found that owing to the presence of a large quantity of non-fibrous cells, the deflaking could increase the content of fines component in the straw pulp with non-fibrous cells markedly by 3.7 percentage points. Also, it presented an ever-decreasing tendency in terms of kink index, curl index, width and silica proportion in its ash. This was opposite to the behavior of the pulp without non-fibrous cells.