The correlation between-94 G/A polymorphism in the dopamine D1 receptor gene and schizophrenia remains poorly understood despite extensive research.This study sought to evaluate the genotypes and allele frequencies of the-94 G/A polymorphism in the dopamine D1 receptor gene by real-time PCR using TaqMan fluorescent probes.One hundred and sixty-two patients with schizophrenia and 101 healthy controls living in Shandong province of China were evaluated.Experimental results showed that the G/A genotype distribution was significantly higher in the schizophrenia patients than in healthy controls.The frequencies of G allele and A allele were not significantly different between the schizophrenia patients and the controls.Thus,the-94 G/A polymorphism in the dopamine D1 receptor gene was found to be associated with schizophrenia in a Chinese Han population from Shandong province.