CNTNAP2, located on 7q35-36.1, encodes a single-pass transmembrane protein mediating cell-cell interactions in the nervous system. CNTNAP2 has been suggested to play an important role in mental diseases such as autism and language disorder. However, we still do not know whether it also confers risk to major psychiatric disorders such as schizophrenia, major depression and bipolar disorder. We analysed single nucleotide polymorphisms (SNPs) previously reported to be associated with autism or language impairment in 1135 schizophrenia patients, 1135 unrelated major depression patients, 1135 unrelated bipolar disorder patients and 1135 unrelated normal controls recruited from the Han Chinese population. We found that the genotypes of rs17236239 were significantly associated with schizophrenia and the alleles of rs2710102 and rs2710117 were significantly associated with major depression. According to the location of significant signals, our study indicated that exon 13-15 of CNTNAP2 may play important roles in both schizophrenia and major depression in the Han Chinese population.