Abstract: An infectious bronchitis virus (IBV) field strain named SC06 was isolated from a chicken flock with typical respiratory symptoms and nephritis lesions. The dwarf embryos were easily founded after inoculation with SC06 isolate in 10-day old SPF chicken embryos. 5 day-old SPF chickens were challenged with SC06 isolate, which could trigger respiratory symptoms and pathological changes, and the S1 and N genes of SC06 were cloned and sequenced. Phylogenetic analysis of the S1 and N gene sequences of the SC06 strain together with the prevailing domestic IBV isolates and the IBV references published in the GenBank revealed that SC06, 4/91 and 7/93B belonged to the same genotype Ⅱ in view of S1 gene, which disagreed with the prevailing IBV strains isolated by our laboratory in recent years, as well as domestic and other prevailing LX4 (genotype Ⅲ), which belonged to the genotype Ⅳ. However, SC06, DY06 and SDGE01 strains including other prevailing IBV isolates belonged to the same genotype Ⅲ in view of N gene, and different from 4/91 and 7/93B (genotypeⅡ). Alignment analysis of S1 nucleotide (amino acid) homology showed that the SC06 and the 4/91 from United Kingdom shared 98.7% (98%) homology, but only shared 75.6%76.0% with the most popular domestic IBV isolates; Further more, the SC06 shared 99.3% (99%), 93.4% (93.6%) homology with the domestic epidemic strain DY06, SDGE01 in view of the N gene nucleotide (amino acid) respectively, while only shared 85.7% (92.4%) with the 4/91. The results of this study suggested that the S1 gene of SC06 maybe originate from 4/91, and the N genes were related to the DY06 types of the prevailing domestic IBV strains, which indicated that the SC06 was a combination between the 4/91 strain and the prevailing domestic IBV strains such as DY06 isolate.