The temporary supporting system also referred as time-dependent structural system during construction, consist of early-age reinforced concrete structures and formwork supporting system. It bears the load including the new concrete weight and the live construction load. A model of continuous beam with spring supports is put forward to analyze the mechanical characteristics of the reinforced concrete structures during construction. Based on-site measuring data, effective bearing area of members were used as statistical objects to calculate statistical parameters of live construction load of concrete buildings. By referring todomestic and foreign achievements, the the standard value of the live construction load was inverted with 95% reliability and standard value of live construction load of 2.5 kN/m 2. is recommended .