The statistical detection is generally used in steganalysis. Comparing with the special stega- nalysis, it has the advantage of flexing. However, it has the disadvantages in large-scale data,and low calculate speed. For the high dimensions of feature attributes, the attributes reduction based on rough set can delete the non-important knowledge while not alter the classification ability of knowledge. The result of experiment shows that the proposed detection technique achieves a comparable precise detection rate as algorithm based on all feature attributes, however, it evidently decreases detection time.