A balancing assembly of an engine may include a crankshaft in which crank pins each connected to a connecting rod, are disposed at both ends thereof, and that is equipped with a counterweight opposite to and corresponding to each crank pin, a balance shaft that is disposed at a distance from the crankshaft and that rotates by the crankshaft, and a balance weight that is eccentrically formed with a balance shaft and that absorbs vibration.