It is well known that Rosa Luxemburg contended the impossibility of realization of accumulated surplus-value in her scheme of reproduction on extended scale. This impossibility (disproportion), however, was due to her equal rate of accumulation in both departments in spite of progressively higher organic composition of capital (c>v), which necessarily results in a lower rate of accumulation in department II. Although it is provided by all the schemes of reproduction on extended scale that the accumulation in department I should determine and forego that of department II, she neglected this law. So it is that O.Bauer himself, unaware of this law, attempted in vain to testify the possibility of realization of accumulated surplus-value under the very same condition as Luxemburg set, and was obliged to transfer part of accumlated surplus-value from department I to department II, which made his scheme inconsistent as the rate of accumulation set in the beginning could not be maintained. Such a view of Luxemburg was a product of her critics on Marx' scheme that his scheme is inconsistent without the continually increasing effective demand. Surely herein is revealed a sort of under-consumptoin theory that in the scheme of reproduction consumption should be prepared for production. She found the origin of this theory in Sismondi, by way of whom indirectly she criticized Len in, pointing out that Sismondi's theory of reproduction rather contains more than the fallacy of Adam Smith's v+s dogma, to say, the exact law of reproduction that it is the income of the past year which must pay for the production of present year. Here she finds prototype of her own theory. But it is not the same conclusion itself that Lenin criticized as induced from above-mentioned dogma? Thus the possibility of accumulation was annulled, capitalism was no more able to develop itself by way of growing production of constant capitals ! There is no other contradiction inherent in capitalism than that of effective demand caused by under-consumption! On the other hand she tried, as her sub-title shows, to clarify the substance of imperialsm. But so long as it depended upon non-realization theory, she again fell into a decisive fallacy. Of course we must allow that she intended to make an analysis on the economic basis of world-wide revolution and proletarian internationalism on those days when an extention of the outlying fields of production brought about capitalistic relations as well as intensified class-struggles all over the world, in which we are so much interested in the light of contemporary crisis. Nevertheless, here too, her critical fallacy of non-realization theory led her to one-sided program of world-wide revolution and proletarian internationalism and made her ignore national problems. On this point lies a practical limit of her theory.