PURPOSE: To provide a bagged corn silage suitable to the transportation and storage for a long term, by adding an organic acid to the corn silage in the bagging thereof, adjusting the pH to a specific value, and removing air from the bag.

CONSTITUTION: In the first step, reaped corn grains are matured in a silo. In the second step, the pH of the corn silage is measured in bagging the corn silage every time. In the third step, an organic acid, e.g. lactic, formic, propionic acid or so-called trub which is a residue of the alcoholic fermentation, is added to the resultant corn silage to reduce the pH to about 3.5W3.0. The resultant silage is then introduced into a vinyl bag, and air is removed to almost a vacuum state. The bag is then sealed up. In this case, the bag is preferably made of a material slightly transmitting light.