NOVELTY - An excrements fermentation system is provided to substantially reduce odor and fermentation time of excrements by agitating livestock excrements stored in a storage tank using the force of the wind so that air is consistently supplied into the storage tank.    DETAILED DESCRIPTION - The excrements fermentation system comprises a storage tank(10) the upper part of which is opened, in which excrements (E) is stored; a bracket(20) which is installed at an opening part of the storage tank(10); and an agitation means(30) which is rotationally installed at the center part of the bracket(20) and agitates the excrements inside the storage tank(10) as it is being rotated by the force of the wind, wherein the agitation means(30) comprises a bearing assembly(31) installed at the center part of the bracket(20), a rotation shaft(32) which is rotationally coupled to the bearing assembly(31) in such a manner that the lower part of the rotation shaft(32) is extended to the bottom of the storage tank(10) while the upper part of the rotation shaft(32) is extended to the upper part of the bracket(20), one or more impellers(33) which are installed on the lower part of the rotation shaft(32) in a rotation radius direction, and a blade assembly(34) which is installed at the upper part of the rotation shaft(32) so that the blade assembly(34) is rotated together with the rotation shaft(32) by wind, the blade assembly(34) comprises a hub fixed to the upper part of the rotation shaft(32), a plurality of rods(34b) which is radially arranged around the hub so that the rods(34b) are integrally rotated along with the rotation shaft(32), and blades(34c) which are installed at the end of the rods(34b) so that the blades(34c) run against wind, the blades(34c) are installed at the end of the rods(34b) in a rotation tangent direction and consisted of a conical metal can the inner part of which is empty, and the excrements fermentation system further comprises a tent which is installed on the bracket(20) to cover the upper part of the storage tank(10).