An enhanced hail detection algorithm (HDA) for the CINRAD/SA radar replaced the original hail algorithm in 2004. The new HDA can estimate the probability of hail (POH, any size), severe hail (diameter greater that 19 mm), and expected maximumsize hail for each detected storm cell. The performance of POH detection is evaluated with Jinan's CINRAD/SA data, using 50% as the warning threshold for the POH parameter, and the verification against hail observations of any size is conducted, and the following accuracy measures are obtained: POD (Probability Of Detection) is 100%, FAR (Falas Alarm Ratio) is 72.2%，CSI (Critical Success Index) is 88%. The expected maximum hail size is 14.6 mm bigger than the actual maximum hail size averagely. Using JinanCINRAD/SA data of 2001 to 2005, the distributive characteristics of the maximum reflectivity in the cases of convective clouds are analyzed. The maximum reflectivities are 59.7, 61.8, 63.9 dBz for hailstorms and 53.8, 54.9, 55.6 dBz for nonhail storms in May, June and July, respectively. So the minimum and maximum reflectivities of a component used in the calculation of the probability of hail are modulated from 45 to 53 dBz, and FAR and CSI are improved obviously. Through adjusting three parameters computing the expected maximum hail size, the expected maximum hail size is close to the actual one.