The present invention relates to a composition for oral administration containing an alkylenedioxybenzene derivative represented by the general formula (I): (wherein m represents an integer of 2 to 5, and n represents an integer of 1 to 3) or an acid addition salt thereof, which allows for duration of the drug concentration in plasma. By dispersing a compound represented by the general formula (I) in a matrix containing a synthetic polymer and/or waxes, a safe and useful pharmaceutical preparation for oral administration having the stable drug releasing property in a living body was obtained.