Recently in Korea, there are increasing use of the environment-friendly material for building elements, and it’s on the tendency that enlarging users demand the application of nature-friendly wood for the fire doors. However, the existing wood fire doors developed are made of mineral insulation such as ceramic wool, some problems may occur because of the increased weight of door, deformable and deflectable insulation in the long-term, and particulates. This study is on the consideration of whether the wood fire door can have fire-resistance performance by reinforcing insulation material. Fire-resistance test and analysis was carried out with each alternatives including fire-retardant board, vermiculite filler, intumescent fire-retardant sheet, intumescent fire-resistance paint and fire-retardant paint for wood use.