Abstract: 1. The vegetative shoot apex of koaliang (Sorghum vulgare Pers.) is similar to the other grasses in that it gives rise successively to the leaf primodia and retains its dome form though it increases somewhat in volume following the completion of the vegetative growth. 2. The vegetative shoot apex transforms into the reproductive one when the 11th or 12th leaf is expanding and the shoot apex, being about 80 cm above the ground, increases rapidly in volume but retains its general form. Then the bract primodia appear at the base of the shoot apex and the branch primodia of the first order become noticeable at the axil of the rudimentary bracts. The branch primodia of the second, the third and the fourth order appear in succession. These characteristics are similar to those of the Panicum milliaceum. 3. The differentiation of the inflerescence is basipetal, while the differentiation of spikelet is acropetal. The order of the differentiation is as follows: the outer glume, the inner glume, the lemma of the first flower, the first flower, the lemma of the second flower, the second flower. The order of the development of the flower parts is the palaea, the stamens, the pistil and the lodicules. 4. During the differentiation of the spikerlet at the appearence of the stamens of the second flower, two kinds of spikelets are differentiated: the spikelets with long rachilla begin to degenerate and the sessile spikelets continue to develope normally. There is a difinite ratio between these two spikelets. At the tip of the branches three spikelets are formed, and two of them will degenerate and one will continue to develope normally. On both sides of the branches, only two spikelets are formed and one of them developes and the other degenerates. The degeneration of the spikelets is similar to that of the bristles in millet.