Abstract: Pores, inclusions and other defects in ceramics are inevitable due to the special process, and they generally ununiformly distribute, this nonuniformity has big impact on ceramic properties. Base on the pore distribution characteristic in ceramics, the parameter uniformity was defined to quantize the uniformity of pore and inclusions distribution, and an image processing method was introduced to confirm the uniformity. According to the image processing results, ceramic was divided to two parts, the effective matrix phase enriched pores and the effective grain phase without pores. Based on interact direct derivative (IDD) estimate, the relationship between strength and uniformity was analyzed. The results indicate that uniformity has significant influence on the strength of ceramic, the strength reduces with uniformity decreasing, especially when the uniformity is lower than 0.2, and influence of uniformity is limited when it is higher than 0.5.