Abstract: Rice of dwarf and sheathed panicle mutant A846 and the wild type are taken as materials. The morphological and microstructure characteristics of stem are compared by using anatomical method. The results are as follows: the dwarf mutant A846 pertain to half-dwarf type, which height is about 38.64 cm on average, preponderating over the half-height of the wild-type, the elongation stage of the mutant represent dwarf character, internode elongation patterns of caulis are similarly the sh-type dwarf mutant, in which the first internode shows specific reduction, the elongation of these cells in the elongation zone immediately above the IM was dissimilar to the wild-type, longitudinal length of parenchyma cells were curtate, also the first internode exhibit markedly, which average is under the corresponding internode of the wild-type, the differentiation of the IM of each internodes of stem was similar to wild-type, as well as the number of internodes and the length of sheath of flag leaf.