The determination of runway capacity is the warrant of confirming the time of constructing new runways in one airfield. This paper defines the concept of takeoff capacity of the independent runway, analyzes the various factors influencing the takeoff capacity and sets up a computation model as a representative of normal distribution problem. This paper still sets up the takeoff capacity calculation model of independent runway and classifies it in theory according to the speed relation of the takeoff aircraft and airway controlled rule, then brings forward the method of fixing on the takeoff capacity. In the calculation model many influence factors such as runway occupancy time, space demand of takeoff aircraft, ATC regulation, wind speed, the length of takeoff commonality district are considered comprehensively. The calculation of the actual takeoff capacity is done with the data of some airport, which verifies the practicability and feasibility of this calculation model.