To investigate the distribution and significance of a coding single nucleotide polymorphism (cSNP) of the novel NIDDM candidate gene,KCNA7 in the population of Northeast China, 97 patients with NIDDM and 141 controls were tested. Genotypes of KCNA7 gene T418M(C/T) were performed by PCR-RFLP, and SSCP was used to detect other unknown variations near the C/T site of KCNA7 gene. As a result, no significant difference was observed in the distribution of genotypes of T418M(C/T) between NIDDM and control group. Clinical biochemical examinations showed no significant difference between genotypes in both INDDM and control group, and no other SNPs were found near the C/T site of KCNA7 gene. This study demonstrates the frequency of this cSNP complies well with the Hardy-Weinberg equilibrium in normal group, T418M(C/T) is only a polymorphic maker of KCNA7 gene,and the possibility of association between NIDDM and KCNA7 can not be excluded.