Objective To analyze the growth phenotype and blood biochemical parameters of chromosome 1 substi-tution mouse strain(CSS1), and investigate their potential of QTL mapping .Methods Body weight, body length, tail length, organ weight of the CCS1 mice were measured at different days to create a growth curve while blood biochemical in -dexes were measured at about the 80th day.Results The CCS1 mice were different from C57BL/6 mice in several inde-xes.Compared with the C57BL/6 mice during different developmental stages , six strains including B6-Chr1KM mice were significantly different in body weight .There were five strains including B6-Chr1CM mice significantly different with C57BL/6 mice in body length, and all of the CSS1 mice were significantly different from C57BL/6 mice in tail length.Part of CCS1 mice were significantly different from C57BL/6 mice in the weight of liver, spleen, kidney and brain.The ALT of female B6-Chr1CM mice was significantly higher than that in the C 57BL/6 mice.The ALP of female B6-Chr1HZ mice was signifi-cantly higher than that in the male C57BL/6 and B6-Chr1KM mice, and was significantly lower than that in the C57BL/6 mice.The TB of male B6-Chr1CM, B6-Chr1SMX and B6-Chr1HZ mice was significantly higher than that of the C 57BL/6 mice.The TG of male B6-Chr1SMX mice and male B6-Chr1TW mice was significantly higher than that in the C 57BL/6 mice. Conclusions The phenotype of Chr1 CSS mice is quite different from commonly used inbred strain C 57BL/6 mice.CCS1 mice show great potential in QTL mapping for their characteristic growth phenotype and blood biochemical indexes .