Canola (Brassica napus L.) recently has received consideration as a forage source for livestock (Lancaster et al., 1990). Canola is reasonably widely adapted and performs well in semiarid countries such as Iran. In addition to its low water requirements and high growth rate, its cultivation season is well matched with environmental condition in Iran. Canola could not reach to stage of blossom in some climates such as cold climate, so farmers could mow and making silage for animal nutrition. Application of silage additives is the most important factor in improving silage quality (Muck, 1993). The main objective of this study was to evaluate the effect of some additives on fermentation parameters, in vitro and in situ dry matter digestibility of experimental whole canola silage.