Abstract：【Objective】To investigate the influence of different pre-pregnancy body mass index（BMI）on blood glucose and serum lipid and pregnancy outcome during pregnancy.【Methods】Clinical records of 1115 singleton pregnant women who underwent obstetric examination and delivered in the first affiliated hospital of Sun Yat-sen University between January 1，2013 and December 31，2013 were collected. The patients were divided into 3 groups based on pre-pregnancy BMI，underweight（G1）：BMI < 18.5 kg/m2， normal weight（G2）：18.5 ~ 23.9 kg/m2，overweight（G3）：≥ 24.0 kg/m2. The characteristics of blood glucose，serum lipid and pregnancy outcome during pregnancy were analyzed and compared among groups.【Results】（1）1 115 cases of pregnant women were Included in the study. The cases of G1 to G3 were 245，757 and 113.（2）With the increase of pre-pregnancy BMI，the blood glucoseof 75 oral glucose tolerance test（OGTT）fasting，1 h and glycosylated hemoglobin（HbA1c）was gradually rising（P < 0.05）. The average blood glucose of 75 OGTT fasting among groups were（4.21 ± 0.34）（4.34 ± 0.35）（4.56 ± 0.50）mmol/L，75 OGTT 1 h were （7.51 ± 1.60），（7.83 ± 1.59），（8.83 ± 1.88）mmol/L，HbA1c were（4.81 ± 0.37）（4.90 ± 0.34）（5.03 ± 0.38）%，there was statistical difference among groups（P < 0.05）. The average FBG of G1 was lower than that of G2 and G3 group（P < 0.05）. The average blood glucose of 75 g OGTT 2 h of G3 was obviously higher than that of G1 and G2 group（P < 0.05）. By Pearson analysis，FBG，75 g OGTT fasting，1 h，2 h，HbA1c had significantly positive relationship with pre-pregnancy BMI（P < 0.05）. The incidence of gestational diabetes of G3 group was higher than that of G1 and G2 group，but the incidence of gestational diabetes between G1 and G2 group had no obvious difference.（3）The triglycerides（TG）of G3 was obviously higher than that of G1 and G2 group（P < 0.05）， the total cholesterol（TC）and high density lipoprotein cholesterol（HDL-C）of G3 was lower than that of G1 and G2（P < 0.05）. But There was no statistical difference about apolipoprotein A1（apoA1），B（apoB），E（apoE），Lp（a），Apo A1/Apo B among groups （P > 0.05）. By Pearson analysis，TG had significantly positive relationship with pre-pregnancy BMI（P < 0.05），but TC，LDL-C， HDL-C had negative relationship with pre-pregnancy BMI（P < 0.05）.（4）With the increase of pre-pregnancy BMI，the weight and head circumference of the newborn was gradually rising（P < 0.05）. The average weight of the newborn among groups were（3.03 ± 0.42），（3.18 ± 0.45），（3.30 ± 0.46）kg，the head circumference were（32.98 ± 1.59），（33.43 ± 1.64），（33.87 ± 1.60）cm，there was statistical difference among groups（P < 0.05）. The shoulder circumference of the newborn of G1 was obviously lower than that of G2 and G3 group（P < 0.05）. Pearson analysis showed that the weight，body length，head circumference，shoulder circumference of the newborn had positive relationship with pre-pregnancy BMI（P < 0.05）.【Conclusion】With the increase of pre-pregnancy BMI， the blood glucose at each time point，serum lipid and growth index of the newborn was gradually rising. We suggest that overweight and obese women should lose weight before pregnancy.