PURPOSE: A roadside tree planting box is provided to build an efficient hydrological cycle environment, to improve the processing efficiency of non-point pollutants, and to be able to accept the ground deformation after construction. CONSTITUTION: A main body (10) is open on the top, and formed with a planting and filtering space inside. A collecting chamber (20) is installed at a relatively lower position than the upper end of the main body within the planting and filtering space. A drain pipe (70) is attached to the collecting chamber, and drains the processed rainfall effluent to a collecting tub, etc. An attachment pipe (710) has a straight pipe (711) installed in the lower part of the collecting chamber, and an extension pipe (712) integrally formed at the end of the straight pipe. A cylindrical support stand (720) is adhered to an inner tube in which the straight pipe contacts with the extension pipe. An end of the support stand is inserted into a cylindrical connector (730). A binding member (740) is c
