Abstract : Natural rubber (Hevea brasiliensis) has a long gestation period and considerable investments. The regression co-efficient of the small holdings and the estate sector reveals that among the five inputs variables, three variables namely, human labour, plant protection and the number of bearing trees have influence on the gross income of the natural rubber in small holdings and estate sector. The Chow’s test inferred that there is a structural difference in production relation between the two farms in the study area. The test of the stability of intercept and slope revealed that the structural difference existed only at slope level between small holdings and estate sector and not at intercept level. With regard to the marginal value productivity, the marginal value productivities of all factor inputs are found to be positive in both plantations. Hence, it indicates that there is a scope for further increasing the input with profit. The resource use efficiency the ratio of marginal value products to their respective cost, it has been found out that the variables human labour and cost of cultivation practices are under utilised whereas in the case of plant protection, plantation of both the farms have been found to be rational in its use. With regard to the return on the investment of capital the net present value indicated the soundness of investment of the natural rubber cultivation in both the plantations. The investment on the natural rubber in the estate sector has been economically more feasible than in the small holdings. The benefit cost ratio reveals the profitability of natural rubber cultivation in both the plantation in the study area.