Objective:To investigate the relationship between fetal growth and cord blood adrenocorticotropic hormone (ACTH) and crotisol. Methods: The newborns were divided into three groups according to their born weight and gestational age,small for gestational age(SGA group,n = 30),lager for gestational age(LGA group,n = 30),appropriate gestational age(AGA group,n = 30). Born body length and body weight of three groups were measured respectively. The levels of ACTH and crotisol in cord blood were measured by radioimmunoassay(RIA). Results: The levels of ACTH in cord blood were (26.46 ± 7.73) ng/ml,(28.64 ± 7.12) ng/ml and (29.30 ± 8.33) ng/ml in LGA group,AGA group and SGA group respectively,and there were no significant differences among three groups(P = 0.336). The levels of crotisol in cord blood were (7.11 ± 2.70) ng/ml,(11.84 ± 3.88) ng/ml and (18.80 ± 5.27) ng/ml in LGA group,AGA group and SGA group respectively,and there were significant differences among three groups(P < 0.01). Conclusion: Crotisol might play an important role in fetal growth.