Fracture test of three point bending beams of non standard reinforced concrete was carried out. The fracture characteristics of three point bending beams of non standard reinforced concrete were studied systematically. Results indicate that the initial load and the maximum load increase with the increase of specimen height. The precritical crack propagation length relative value is independent of specimen height. Similar to the double K fracture toughness, both the initiation fracture toughness and the unstable fracture toughness are not change with the increase of specimen height, which can be regarded as constants to three point bending beams of non standard reinforced concrete.