One of the agricultural waste that can be used optimally is corn straw, because it can be used by the farmer in the dry land as the replacement of grass. The research was conducted determine the effect of different molasses level fermentation time on the physical characteristics of silage corn straw (Zea mays). This research was arranged  in factorial completely randomized design, the first factor was molasses level (0; 5 and 10%) and the second factor was fermentation time (0; 14 and 28 days). The observed variables are the physical characteristics of silage (colors, smell, texture) and the presence of fungi. Data were analyzed by analysis of variance and differences between the treatments were tested by Duncan’s Multiple Range Test. The result showed th at different molasses levels was significantly effects (P<0,01) to the colors of silage. There was a significant interaction (P<0,01) between fermentation time and molasses level on silage smell parameter. Fermentation time showed did not significantly effects (P>0,05)  on  the  texture  of  silage.  Molasses  levels  and  the  28  day  of  fermentation  time  resulted  fungi  with  presentation0% = 2,64%; 5% = 1,60%; 10% = 0,91%. It can be concluded that different fermentation time and molasses levels influenced andeffected to the smell characteristic of corn straw silage but did not effected on the color and texture