Changes in the activity of ribulose 1,5-bisphosphate carboxylase (RuBPC), soluble proteins and l‘*C02 fixation were studied in Vigna sinen.sis L. seedlings grovvn under nonnal and ultraviolet-B (UV-B) enhanced radiations at 10, 20, 30 and 40 ^C. The seedlings grown under nonnal radiation showed a progressive increase in enzyme activity, soluble protein and *‘*C02 fixation with an increase in temperature from 20 to 40 oC, while seedlings grown under UV-B enhanced radiation showed gradual decrease in these parameters with a maximum effect at 20-30 oC, At 40 oC, the inhibition was less. RuBPC activity, soluble protein content and '‘♦CO2 fixation showed parallel increases with increasing period of UV-B treatment at 10 oC, The polypeptide pattem of crude leaf extract showed progressive decrease in the level of 55 and 13 kDa polypeptides with the time of UV-B treatment at 20 and 30 °C. However, no such loss in these polypeptides was observed at 10 oC, and at 40 oC only a marginal loss in the level of 13 kDa polypeptide had occuned.