To analyze the relationship between serum adipokine Apelin level of pregnant women with gestational diabetes mellitus and their glucose and lipid metabolism (GDM). Methods: 60 pregnant women with GDM were selected in observation group and another 60 healthy pregnant women were selected in control group from January 2019 to February 2020. The levels of serum adipokine Apelin, fasting plasma glucose（FPG), 1h and  2h PG of OGTT, and fasting insulin (FINS), the values of insulin resistance index, such as homeostais model assessment of insulin resistance（HOMA-IR) and insulin sensitivity index (ISI), the value of beta cell function index, such as homeostasis model assessment of beta cell (HOMA-beta), and the levels of total cholesterol (TC), triglycerides (TG), low density lipoprotein cholesterol（LDL-C), and high density lipoprotein cholesterol（HDL-C)of the women in the two groups during the second trimester of pregnancy (24-28 gestational weeks) and during the third trimester of pregnancy (29-32 gestational weeks) were detected. According to the HbA1c level after treatment, the women in the observation group were further divided into group A (women with HbA1c>6.5%) and group B (women with HbA1c≤6.5%), and the serum adipokine Apelin level of the women in the observation group after treatment was also detected. Results: The levels of FPG, 1h and 2h PG, and FINS, and the HOMA-IR value of the women in the observation group during the second and the third trimester of pregnancy were significantly higher than those of the women in the control group, but the ISI level and the HOMA-β value of the women in the observation group were significantly lower. The levels of TC, TG, and LDL-C of the women in the observation group during the second and the third trimester of pregnancy were significantly higher than those of the women in the control group, but the HDL-C level of the women in the observation group was significantly lower. The serum adipokine Apelin level of the women in the observation group during the second or the third trimester of pregnancy (478.23±32.77 pg/ml or 495.62±35.14 pg/ml) was significantly higher than that (389.19±22.56 pg/ml or 392.51±23.55 pg/ml) of the women in the control group (all P＜0.05). The levels of FPG, 1h and 2h PG, and FINS, the HOMA-IR value, the levels of TC, TG, and LDL-C, and the serum adipokine Apelin level of the women in the observation group during the third trimester of pregnancy were significantly higher than those during the second trimester of pregnancy, but the ISI and HDL-C levels and the HOMA-β value of the women in the observation group during the third trimester of pregnancy were significantly lower than those during the second trimester of pregnancy (all P＜0.05). The serum adipokine Apelin level (503.61±40.17 pg/ml) of the women in group A was significantly higher than that (399.89±23.29 pg/ml) of the women in group B (P＜0.05). Pearson correlation showed that serum adipokine Apelin level of the women with GDM was positively correlated with their FPG level, 1h and 2h PG level, FINS level, HOMA-IR value, TC level, TG level, or LDL-C level of pregnant women with GDM, but was negatively correlated with their ISI level, HDL-C level, or HOMA-β value (all P＜0.05). Conclusion: The level of serum adipokine Apelin of the pregnant women with GDM abnormally increases, and decreases after treatment, and which the elevated serum adipokine Apelin level may be closely related to the disorder of glucose and lipid metabolism of these women.