Abstract: This experiment was conducted to study characteristics of molecular epidemiology of avian infectious bronchitis virus (IBV) in Shandong province of China between 2006 and 2008. The complete S1 gene and N gene of fourteen IBV strains isolated in Shandong were amplified using RTPCR method.Then they were sequenced and S1 gene was analyzed by restriction fragment length polymorphism (RFLP). Results indicated that these Shandong IBV isolates were classified into three groups according to their RFLP patterns obtained using the restriction enzyme HaeⅢ. Eleven of fourteen isolates were similar to the LX4 RFLP pattern, which is a common pattern in China. The RFLP patterns for 2 of 14 isolates corresponded to the patterns of IBV Massachusetts strains. One isolate showed variant RFLP pattern. They were characterized by comparison with eleven reference strains. The result of S1 gene analysis demonstrates that Shandong IBVs, which were mainly nephropathogenic, were divided into three genotypes. The results of S1 glycoprotein genes analysis and RFLP analysis were similar. Eleven field viruses clustered together with LX4type strains, having 954%-997% nucleotide identity within the group, and two isolates had very close sequence relationship with Massachusetts strains. One isolate formed novel genotype in Shandong. Phylogenic analysis of N gene sequences revealed that twelve field viruses clustered together with LX4type strains with high identity and two isolates had very close sequence relationship with Massachusetts strains. These findings suggest that not only point mutations, insertions and deletions but also a recombination events having contributed to the genetic diversity and emergency of IBV variants in Shandong.