Abstract: Microstructure and performance were investigated on aged 2124 alloy at 190 and 170°C with or without added load by means of TEM, tensile testing. Due to dislocations providing enough misfits for the nucleation of S phases, equivalent S phase distribution in various directions was obtained. Load did not significantly impact preferential orientation of the S phase. However, length of the S phase in aged samples with load was shorter than that without load. Load had no significant impact on preferential orientation and length of GPB. Growth rate of the S phase aged at 190°C was faster than that at 170°C with load. Because of a large amount of fine S phase precipitation, yield strength of the aged alloy with load was larger than that without load.