Objective To identity the prevalence of Helicobacter spp． infection in laboratory mice and laboratory rats in the area around Shanghai，and provide reference and basis for the establishment of Chinese laboratory animals grades and monitoring standards． Methods A total of 352 mice ( 101 clean grade mice，251 SPF grade mice) and 101 rat ( 69 clean grade rats，32 SPF grade rats) obtained from the area around Shanghai were detected by polymerase chain reaction ( PCR) ． 88 mice ( clean grade mice，62 SPF grade mice) and 165 rats ( 84 clean grade rats，81 SPF grade rats) were detected by enzyme linked immunosorbent assay ( ELISA) ． Next，the positive rate of the two methods in 88 mice and 101 rats were compared． Results PCR detecting percentage in mice and rats were as follows: the average positive rate of mice was 35. 8% ( 126 /352) ，among them，the positive rates of clean grade rats and SPF grade mice were 51. 5% ( 52 /101) and 29. 5% ( 74 /251) ，respectively． The average positive rates of rats were 70. 3% ( 71 /101) ，among them，the positive rate of clean grade and SPF grade were 69. 6% ( 48 /69 ) and 71. 9% ( 23 /32 ) ，respectively． ELISA detecting percentage in mice and rats as follows: the average positive rate of mice were 15. 9% ( 14 /88) ，among them，the positive rates of clean grade and SPF grade mice were 19. 2% ( 5 /26) and 14. 5% ( 9 /62) ，respectively． The average positive rate of rats was 52. 7% ( 87 /165) ，among them，the positive rates of clean grade and SPF grade rats were 53. 6% ( 45 /84) and 51. 9% ( 42 /81) ，respectively． The positive rates of 88 mice tested by PCR were 72. 7% ( 64 /88 ) and by ELISA 15. 9% ( 14 /88 ) ． The positive rates of 101 rats detected by PCR were 70. 3% ( 71 /101 ) and by ELISA 49. 5% ( 50 /101 ) ． Conclusions Helicobacter spp． infection exists in laboratory mice and laboratory rats in the area around Shanghai． The PCR assay of feces is more sensitive than the examination of the serum antibody against Helicobacter spp．