A tension-compression beam fatigue test under continuous sine wave alternating loading for AC-13 was conducted to understand fatigue damage characteristics of an actual asphalt pavement structure under tension and compression stresses. Ten sion-compression fatigue damage characteristics of asphalt mixtures were investigated using phenomenology based on basic theory of damage mechanics. Tension-compression fatigue test method and influencing factors were introduced; and tension-compres sion fatigue equation was established via fatigue test results. A tension-compression fatigue damage model was developed based on the damage variable defined by elastic modulus. Damage parameters were determined by fitting fatigue test data. Tension compression fatigue damage evolution equation regarding stress level was constructed. Results show the following. (1) Fatigue damage parameters 0' and f3 increase with stress level; and relationship between damage parameters and stress level is linear.(2) Tension-compression fatigue damage evolution has approximately three stages: damage initiation, stable growth, and unsta ble failure. (3) The greater the nominal stress level is, the lower the curve of the damage evolution curve is, and the less fa tigue damage evolution speed varies with life radio.