Background: Gestational diabetes mellitus can occur in pregnant women because during pregnancy changes in metabolism of carbohydrates, proteins, and fats. These physiological changes are due to an increase in the production of antagonistic hormones that are insulin resistant. Objective: This study aimed to determine the effect of N-hexane fraction, ethyl acetate fraction and ethanol fraction of jackfruit seeds (Artocarpus heterophyllus Lam.) on reducing blood sugar levels in diabetic rats in streptozotosin-induced pregnancy conditions. Materials and Methods: The treatment group consisted of the normal group, positive group, metformin group (10.27 mg/200 g BW rat), insulin group (1 IU/rat), N-hexane fraction group (3.2 mg/200 g BW rat), ethyl acetate fraction group (30.13 mg/200 g BW rat), ethanol group (45.67 mg/200 g BW rat). The parameters observed were a decrease in blood sugar levels on day 7 and day 14. Data of blood sugar levels obtained were analyzed using one-way ANOVA and followed by the Tukey test. Results: The result showed that there was a decrease in blood sugar in the metformin group of 59.91%, the insulin group 81.5%, the N-hexane fraction group of 23.15%, the ethyl acetate fraction group of 45.25% and the ethanol fraction group of 48.91%. The percentage decrease in blood sugar levels showed that the provision of a comparable ethanol fraction (P>0.05) with the ethyl acetate fraction but not comparable with a positive group that can reduce blood glucose levels in diabetic rats in the condition of pregnancy. Conclusion: Based on these results, fraction jacfruit seeds have activities but not comparable with positive controls to decrease blood sugar levels in Gestational diabetes mellitus rat.