Objective to observe the clinical effect of combined spinal and epidural anesthesia in different doses of isobaric bupivacaine combined with fentanly for caesarean delivery in black african maternal with pregnancy-induced hypertension and explore the optimal dosage of local anesthetic. Methods 75 black maternals with mild or severe preeclampsia, ASA (Ⅱ～Ⅲ) grade, who were scheduled for caesarean delivery, were completely randomized into three groups (25 in each group) according to different doses of 0.5% isobaric bupivacaine: group A(8 mg), group B(10 mg) and group C(12 mg). The heart rates, systolic pressures, diastolic pressures and saturation of pulse oximetry at the timepoints of 5 min before spinal anaesthesia and post-spinal anaesthesia (5, 10, 15, 30 min) were respectively recorded. The anesthetic effects, sensory blocked level, side effects such as hypotension and nausea as well as vomiting, administration of anesthetic in epidural space, dosage of ephedrine, Apgar score of neonate at 1 and 5 minute were also recorded. Results After spinal anaesthesia,the SBP and DBP decreased significantly and reached a nadir within 5 minutes in three groups, the blood pressure in group C decreased more significantly than group A and B(A:SBP[141.74±11.82] mmHg, DBP[95.77±11.28] mmHg, B:SBP[139.32±12.26] mmHg,DBP[94.74±11.89] mm Hg, C: SBP[125.25±15.76] mmHg，DBP[87.75±12.21] mmHg, P<0.05); the cases of sensory blocked level in T6 were more in group B and C than group A(A:17 cases, B:23 cases C:24 cases, P<0.05) and the cases of sensory blocked level in T4 were the most in group C(A:2 cases, B:3 cases C:13 cases, P<0.05); the anesthetic effects was better in group B and C than group A(A:64 percent excellence, B:88 percent excellence, C: 100 percent excellence, P<0.05); the incidence of hypotension(A:24 percent, B:32 percent, C: 88 percent) and nausea as well as vomiting(A:6 percent, B:7 percent, C: 15 percent) and were highest in group C(P<0.05); in group C more ephedrine was used compared to other two groups [A: （10.20±4.58）mg, B:（14.37±5.40）mg, C:（53.48±10.87）mg, P<0.05 ]; cases of anesthetics administrated in epidural space was more in group A than group B and C(A:9 cases, B:1 case C:0 case, P<0.05). Conclutions For caesarean delivery in black african maternals with pregnancy-induced hypertension, CSE with 0.5% isobaric bupivacaine 10 mg plus fentanly 20 µg intrathecally provided better anesthetic effect with less side reactions, it was the appropriate dosage of local anesthetic.