Type 2 diabetes (T2D) mellitus is a metabolic disorder characterized by chronic hyperglycemia and insulin resistance. It has been a worldwide public health problem, which is increasing rapidly, especially in developing countries such as China. The ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) gene, also known as plasma cell membrane glycoprotein 1, has been reported by genetic association studies as being associated with T2D and obesity in various populations, such as Caucasian and African American. However, there are also some controversial results in Asian populations. Our study tried to examine the associations between ENPP1 and T2D and obesity. Rs1044498 (K121Q) and rs7754561 were genotyped in 1912 patients and 2041 control subjects through TaqMan technology on the ABI7900 system. They showed no statistical association with T2D, obesity or any metabolic quantitative traits. Our meta-analysis result was consistent with it. Our study did not replicate the positive association found previously and suggested that K121Q of ENPP1 might not have a major role in the susceptibility to T2D or obesity in the Chinese Han population.