Application of suitable substrates is important for growing ornamental plants. Mushroom compost is considered as a waste in mushroom production. An experiment was done on completely randomized design by treatments containing 50% cocopeat + 50% mushroom compost, 50% compost from forest trees+ 50% mushroom compost, 50% perlite+ 50% mushroom compost, 50% leaf compost+ 50% mushroom compost and control substrate (70% agricultural soil+ 20% leaf compost+10% rice husk) in 4 months April, May, June and July to evaluate the effect of mushroom compost in mixing to other substrates on growing characteristics of Ficus benjamina. The result showed that the effect of substrate was significant on factors such as new leaf number, length and width of leaves while it wasn't significant for factors such as height, stem diameter and chlorophyll content. Also, the effect of time was significant on new leaf number, height, length and width of leaves, and stem diameter. The interaction of substrates and time were significant on stem diameter, new leaf number, length and width of leaves too, but they weren't significant on plant height. Evaluation of results showed that the best substrates for mixing to mushroom compost were cocopeat, perlite and compost from forest trees. Furthermore, growing characteristics were better in June and July than other months, while addition of stem diameter was more in May. Therefore, substrates such as perlite, cocopeat and compost from forest trees were recommended in combination with mushroom compost.