Cell wall polysaccharides' occurrences in two internodes of different development stages in M. lutarioriparius stem were analyzed and three major differences between them were identified by cell wall polysaccharide probes. Deposition and modification of cell wall polysaccharides during stem development affect biomass yield of the Miscanthus energy crop. The distribution patterns of cell wall polysaccharides in the 2nd and the 11th internodes of M. lutarioriparius stem were studied using in situ immunofluorescence assay. Crystalline cellulose and xylan were present in most of the stem tissues except phloem, where xyloglucan was the major composition of hemicellulose. The distribution of pectin polysaccharides varied in stem tissues, particularly in vascular bundle elements. Xylogalacturonan, feruloylated-1,4-β-D-galactan and (1,3)(1,4)-β-glucans, however, were insufficient for antibodies binding in both internodes. Furthermore, the distribution of cell wall polysaccharides was differentiated in the two internodes of M. lutarioriparius. The significant differences in the pattern of occurrence of long 1,5-α-L-arabinan chain, homogalacturonan and fucosylated xyloglucans epitope were detected between the two internodes. In addition, the relationships between probable functions of polysaccharides and their distribution patterns in M. lutarioriparius stem cell wall were discussed, which would be helpful to understand the growth characteristics of Miscanthus and identify potential targets for either modification or degradation.