【Abstract】 Objective To investigate the relationship between maternal hypothyroidism and neonatal hypothyroidism and the effect of TSH goaldirected therapy on the incidence of neonatal hypothyroidism. Methods 58 pregnant women with hypothyroidism and 67 pregnant women with subclinical hypothyroidism treated in our hospital between January 2012 and January 2015 were included in the clinical hypothyroidism group and subclinical hypothyroidism group, respectively. Another 60 pregnant women with normal thyroid function underwent pregnancy test in the hospital during the same period were selected as control group. Among 125 pregnant women complicated with hypothyroidism, 95 cases were treated with levothyroxine (LT4) (LT4 treatment group), of whom 71 cases of serum thyroid stimulating hormone (TSH) reached the standard (standard group), while 24 cases of TSH (nonreaching standard group) did not and 3 cases missed LT4 treatment (non LT4 treatment group)On termination of pregnancy, the neonatal thyroid function parameters were compared between LT4 treatment group, non LT4 treatment group and control group. The incidence rates of neonatal hypothyroidism in all groups were recorded. Results The neonatal TSH in non LT4 treatment group was higher than that in LT4 treatment group and control group (P＜ 005). There was no significant difference between LT4 treatment group and control group (P ＞ 005). There were no significant difference in serum free thyroxine (FT4) between pregnant women in the three groups (P ＞ 005). The incidence of neonatal hypothyroidism in non LT4 treatment group (2333%) was higher than that in LT4 treatment group (842%) and control group (0).There was no significant difference between LT4 treatment group and the control group (P ＞ 005). There was no significant difference in the incidence of neonatal hypothyroidism between clinical hypothyroidism group and subclinical hypothyroidism group (P ＞ 005). The incidence of neonatal hypothyroidism in standard group (423%) was lower than that in nonreaching standard group (2083%) (P＜ 005). Conclusion Pregnancy complicated with hypothyroidism will increase the incidence of neonatal hypothyroidism. LT4 treatment can reduce the incidence of neonatal hypothyroidism, especially in pregnant women with standard TSH.