Sunflower seed rust is an emerging disease found in the production in recent years. The disease is characterized by irregular rust spots on sunflower husk. Its occurrence had seriously affected sunflower appearance for seeds serving, and was becoming a bottleneck for sunflower industry. Field experiments were carried out in Wulateqian County and Wuyuan County in Bayannur, Inner Mongolia, China. In these areas, sunflower seeds suffered seriously. The resistance to seed rust spots was evaluated on 44 sunflower cultivars, including 39 confectionery sunflowers and 5 oil sunflowers. The diseased scales (0~4) were scored based on following criterion. level 0 = No rust spot of seeds on the whole capitulum, level 1 =Rust spots on the seed surface of all rust-spotted seeds account for an average of 1% to 25%, level 2 =The proportion is an average of ≧25%, level 3= The proportion is an average of ≧50%, level 4 = The proportion is an average of ≧75%. Seed rust spot rate (%) = number of rust spots on seeds / number of seeds × 100. For each varieties, three replications with 15 plants were scored. Results showed that, among the confectionery sunflowers in Wulateqian County, rate of seed rust spots of Sairui 1 was the lowest (< 25%). 6 varieties had lower rates between 25% and 50% (such as JK 103, LJ 188, LD 5009, etc.), the others were more than 50%. Considering the severity levels, 20 varieties were in level 1, but with the disease rate ranging from 17.30% to 88.63%. In Wuyuan County, the disease rate was 61.02% to 99.63%, significantly higher than the same varieties in Wulateqian County, but with lower level. Only 10 varieties were in level 1 such as 3638C. For oil sunflower, 4 varieties were lower than 25%, except for XKS2029. In addition, rust occurrence of the same variety at different sowing times also showed significant differences. For example, for SH361, the rate was 34.49% on the sowing date of May 27th, but 98.47% on June 20th. It indicated that different sowing dates effected the occurrence of seed rust spots.