For localized soft tissue sarcomas (STS) of the extremities, limb-sparing or conservative surgery with perioperative radiotherapy (RT) is the standard of care. However, several challenges persist. Notably, there are exceedingly high rates of distant metastatic recurrence even after surgical resection and RT, and conventional fractionated radiotherapy has a prolonged duration (5-6 weeks). With advancements in RT technology, the gradual expansion of hypofractionated radiotherapy regimens enables significantly shorter treatment durations. Promising recent reports on 1-week hypofractionated RT regimens, such as the 5X5 Gy RT regimens, have demonstrated reasonable local control and acceptable toxicity in resectable STS.Addressing the challenge of distant metastasis, previous studies have indicated that AI regimens are expected to eliminate micrometastases and improve survival in patients with STS at a high risk of distant relapse. Therefore, the goal of this clinical trial is to investigate whether hypofractionated RT combined with a sequential chemotherapy（AI regimens）can enhance short-term treatment efficacy for extremity STS patients without compromising local control rates and increasing related toxicities