The tire lateral force was influenced by tire side slip angle, vertical force, camber angle, longitudinal slip ratio, wheel speed, tire pressure and so on, and was one important part of vehicle lateral dynamics. Based on the research of tire test data, the relation between tire lateral force and all affecting factors was described in detail. The characteristic diagram of the lateral force versus the tire slip angle showed a degressive shape. An increase of wheel load did not lead to a proportional increase of the transferable lateral force. The degressive dependence of the lateral force upon the slip angle as well as upon the wheel load was very important for the driving behavior and the tuning of suspension, as would be clarified by a numerical example. The relation between tire lateral force and camber angle was very important for suspension camber recovery property, and a numerical example was used to clarify.