PCR single-strand conformation polymorphism (SSCP) and DNA sequencing techniques were used to analyze the genetic polymorphism of mannose-binding lectin (MBL) gene 3 introns in Hu sheep. The results showed that 3 introns of MBL gene had polymorphism, 3 genotypes were identified in intron1, which were controlled by 2 alleles, respectively; 3 genotypes were identified in intron2, which were controlled by 2 alleles, respectively; 3 genotypes were identified in intron3, which were controlled by 2 alleles, respectively; 6 new single nucleotide polymorphisms(SNPs) mutation sites were found, g.288T>A in intron1, g. 1091 T>C, g.1096A>C, g.1770G>C in intron 2, g.2297C>T, g.2331G>A in intron3. Use ELISA to detect MBL serum level in Hu sheep, then use One-way ANOVA analyze the relationship of different genotypes and MBL serum level. And the result showed that the MBL serum level of AA genotype was higher than BB genotype (P<0.05) in intron1, CC genotype was higher than DD, GG genotype was higher than HH (P<0.05) in intron2. So, AA, CC and GG genotypes may be related to disease resistance; BB, DD and HH genotypes be related to disease susceptibility. The point mutation in intron3 couldn"t lead to the change of MBL serum level.