Purpose: Mutations in PAX6 are the major cause of aniridia. Only a few PAX6 mutations in Chinese have been reported. This study is to identify novel mutations in PAX6 of Chinese patients with aniridia. Methods: Aniridia patients were collected from 11 Chinese families, and genomic DNA was prepared from venous leukocytes. The coding regions of PAX6 were analyzed by direct sequencing of PCR products. Variations detected were further evaluated in available family members as well as in controls by using heteroduplex-SSCP analysis. Results: Four novel mutations including c.141+1G>A, c.184-3C>G, c.542C>A (Ser181X), and c.562C>T (Gln188X) and one known mutation c.120C>A (Cys40X) were identified in PAX6 of five unrelated patients with aniridia. All five mutations are expected to generate null alleles of PAX6. Varied ocular phenotypes were observed in different patients within families. Conclusions: We identified four novel mutations and 1 known mutation in the human PAX6 gene. These results expand the mutation spectrum in PAX6 and enrich our knowledge of genotype-phenotype relation due to PAX6 mutations.