To cite this paper: Jian, G., Y. Cuijun and L. Guihe, 2015. Analysis to wilting and mixed silage effect on naked oats(Avena nuda) and alfalfa (Medicago sativa AbstractNutritional evaluation of fresh and wilted silage made of Naked Oats (Avena nuda L.) and Alfalfa (Medicago sativa L.) in different proportions (0:1, 1:0, 1:1, 2:1 and 1:2) was carried out in present study. The changes between fermentation quality and nutrition composition were observed after 60 days. The results based on sensory evaluation showed that the wilted silage was better than fresh silage, and the quality of silage improved gradually with the increase of the proportion of naked oats. The pH value and the content of propionic acid (PA) of wilted silages had no significant difference (P>0.05), and following the increased ratio of naked oats, the pH value and the content of PA of mixed silages were significantly decreased (P<0.01).Wilted and the increased ratio of naked oats significantly increased the content of lactate (LA) (P<0.01), and reduced the content of butyrate acid (BA) and ammoniacal nitrogen/total nitrogen (NH 3 -N/TN) (P<0.01). The most significant nutritional effect (decrease or increase) was observed when naked oats and alfalfa were mixed in 2:1 ratio. The content of dry-matter (DM) and water-soluble carbohydrate (WSC) had significant change (P<0.01) and the content of crude ash (Ash) also had significant change (P<0.05), and other nutrient contents had no significant change (P>0.05) in wilted treatments. With the increase of alfalfa in mixed silage, the content of crude protein (CP) was significantly increased (P<0.01) and the content of WSC and neutral detergent fiber (NDF) were decreased (P<0.05), and other nutrient contents had no significant change (P>0.05). The interaction of wilted and mixed ratio showed significant effect on pH value (P<0.05), the content of LA (P<0.01), PA (P<0.05) and BA (P<0.01), and had no significant effect on the contents of AA and NH 3 -N/TN (P>0.05). Sensory evaluation revealed that fermentation quality and nutritional composition of mixed silages of naked oats and alfalfa were better than alone, and the quality of wilted silages was better than fresh silages.