Oats germplasm were the important basis of oat breeding. The research of oats genetic diversity not only contributed to the collection, management and utilization of germplasm, but also benefit to the conducting of the research of core collection. Genetic diversity of 74 accessions of hulled and naked oat,which were from different sources，were planted in Hohhot in Inner Mongolia Science and Technology Park, and analyzed by cluster analysis and principal component analysis for the purpose of investigating Genetic Diversity of Agronomic Characters. The result showed that the genetic diversity index of all traits were relatively large, grain weight per plant had the highest genetic diversity index, followed by TGW and panicle length .The variation coefficient of the tillering number per plant was the maximal，while grain weight per plant and the main spike grain weight was the next. The minimum genetic diversity index was presented by plant height. According to genetic difference of each characteristic among varieties, the 74 Germplasm Resources could be classified into 5 categories by cluster analysis, 36 accessions of hulled oat were be classified into 2 categories. and 26 accessions of naked oat were classified into 2 categories．7 accessions of hulled oat and 5 naked oat were classified into 1 category．The first group can be used as parents of high-yield breeding objectives,the third group can be used as parents of grain shape breeding objectives,the fourth and fifth can be used as parents of plant height and spikelet breeding objectives. The principal component analysis on quantitative characters showed that the accumulative contribution rate of the first four principal components accounted for 86.27% of the total variation accounted, the first principal component mainly reflected the yield ,while the second principal component reflected the grain shape.The third and fifth principal component reflected tiller number and plant height, respectively.