Abstract: To discuss the relationship of LYZ gene with growth and laying performance traits, the second generation divergent lines of J+ and J-female bred by Jinghai yellow chicken breeding center were used in the present study. Three SNPs (G111A, T1426C, C1492T) in exon1 and exon2 were discovered by sequencing. Multi-contrast analysis showed that the birds with genotype AA were significantly higher than those with genotype GG and GA for body weight at 12 and 16 weeks of age, and smaller than those for age of first egg (P<0.05). The birds with genotype TT were significantly lower than those with other genotypes for body weight at 4 and 8 weeks of age and body weight of first egg, while the birds with genotype TN were significantly higher (P<0.05). Analysis results indicated that the genetic effects of haplotypes on body weight of 4 to 16 weeks of age and body weight of first egg were significant. Population genetic analysis indicated that the frequency of the genotypes were significantly different in the two lines (P≤0.05). It was concluded preliminarily that chicken LYZ gene had important effects on growth process in the chicken or it closely linked with those genes affecting growth.