Background: Ropivacaine is a local anaesthetic agent which is a long acting amide, a pure S (-) enantiomer of propivacaine. It has reduced potential for neuro and cardiotoxicity and safer than bupivacaine. This drug is less lipid soluble and blocks sensory neurones to greater extent than motor nerves. Mother undergoing caesarean section will be mobile early, so that breastfeeding and other things will be easy for mother. We have designed present study to evaluate the sensory and motor characteristic and the advice effect of spinal 0.75% isobaric ropivacaine 15 mg compared to 0.5% bupivacaine 8 mg for caesarean section. Material and Method: Based on exclusion and inclusion criteria 80 parturients were enrolled for this study. The parturients were randomly allocated into two groups. We have used computer generated randomization table for randomization. Each group consists of forty parturients. Parturients who have received Bupivacaine were allocated in Group B and parturients who have received Ropivacaine were allocated in Group R. Result: Motor block characterisation in two groups, the mean time for onset of grade III block was 7.54 + 1.2 min in Group R and 3.34 + 2.86 min in Group B, This difference was statistically significant. Total duration of block in Group R was 98.67 + 12.38 and 121.74 + 17.38 min in Group B. This finding is significant statistically. Mean of total duration of analgesia was 164.66 + 19.68 min in Group R and 149.86 + 21.72 min in Group B. The value p value was 0.001. Conclusion: Based on our observation we can conclude that onset of sensory block was faster with bupivacaine, time to repression of sensory block was shorter with ropivacaine. The total duration of sensory block was little higher in bupivacaine but duration of analgesia were compared in two groups. Onset of motor block was late and duration of motor block was significant early in ropivacaine group. Haemodynamic parameter was comparison in both groups.