There are currently no diagnostic methods in vitro for aspirin-induced chronic urticaria (AICU) except for the provocation test in vivo. To identify disease markers for AICU, we investigated the single nucleotide polymorphism (SNP) of the promoter loci of high-affinity IgE receptor (FcεRIα) and CD203c expression level in Chinese patients with AICU. We studied two genotypic and allelic frequencies of rs2427827 (-344C/T) and rs2251746 (-66T/C) gene polymorphisms of FcεRIα in 20 patients with AICU, 52 subjects with airway hypersensitivity without aspirin intolerance, and 50 controls in a Chinese population. The results showed that the frequencies of two SNPs (-344C>T, -66C>T) were similar to the normal controls. The allele frequency of -344CC was significantly higher in the patients with AICU compared to those with airway sensitivity (p=0.019). We also studied both histamine release and CD203c expression on KU812 cells to assess aspirin-induced basophil activation. We found that the activity of basophil activation of AICU was significantly higher in the patients with AICU compared to those with airway hypersensitivity without aspirin intolerance. The mean fluorescence intensity of the CD203c expression were 122.5±5.2 vs. 103.3±3.3 respectively, (p<0.05), and the percentages of histamine release were 31.3%±7.4% vs. -24.0%±17.5%, (p<0.05) respectively. Although the mean fluorescence intensity of CD203c expression and the percentage of histamine release were significantly up-regulated by aspirin, they were not affected by anti-IgE antibodies. These results suggest that a single SNP of FcεRIα (-344C>T) is less likely to develop AICU and the basophil activation activity in the sera by measuring CD203c expression can be applicable to confirm the diagnosis of AICU.