Bay leaf (Syzygiumpolyanthum) or Daun Salam is one of the plants that has many benefits, one of them is to reduce blood pressure. The aim of this study is to prove the effect of adding nanoparticles supplementation of bay leaf (Syzygiumpolyanthum) to systolic and diastolic blood pressure in pregnancy hypertension.The study was quasi-experiment. 39 respondents were divided into 19 pregnant women in intervention group and 20 pregnant women in the control group. The intervention was given for 14 days by consumingnifedipine 10mg plus 80mg bay leaf nanoparticle capsules to the intervention group.The results of data analysis showed a decrease in systolic blood pressure (p = 0.000) and diastolic blood pressure (p = 0.004) when compared with the control group, which means that there were differences in the mean systolic and diastolic blood pressure between the two groups after treatment. The addition of bay leaf nanoparticle supplementation 1x80 mg for 14 days affected the decrease in systolic and diastolic blood pressure in pregnancy hypertension. So that the supplementation of bay leaf nanoparticles can be used as adjunctive therapy in pregnancy hypertension