Toxoplasma gondii is an important protozoan parasite that infects most species of warm:blooded animals worldwide,including humans and birds.The prevalence ofT.gondii infection in birds has epidemiological significance because birds are indeed considered as a good indicator of environmental contamination by T.gondii oocysts.In this study,the prevalence ofT.gondii in 313 house sparrows in Lanzhou,northwestern China was assayed by the modified agglutination test (MAT).Antibodies to Toxoplasma gondii were found in 39 (12.46%) of 313 samples (MAT titer≥ 1:5).Tissues of heart,brain and lung from the 39 seropositive house sparrows were tested for T.gondii DNA,11 of which were found to be positive for the T.gondii B 1 gene by PCR amplification.These positive DNA samples were typed at 9 genetic markers,including 8 nuclear loci,i.e.,SAG 1,5: and 3: SAG2,alternative SAG2,SAG3,GRA6,L358,PK1,c22:8 and an apicoplast locus Apico.Of them,4 isolates were genotyped with complete data for all loci,and two genotypes (Type Ⅱ variants: ToxoDB #3 and a new genotype) were identified.These results show that there is a potential risk for human infection with T.gondii in this region.To our knowledge,this is the ?rst report ofT.gondii seroprevalence in house sparrows in China.