Hot compresses can be applied to chondromalacia patella for two main reasons: First, chondromalacia patella is formed mainly due to patellofemoral joint underdevelopment, patellofemoral joint instability, and excessive pressure and friction in the patellofemoral joint, which leads to degeneration of the cartilage. In the process of hot compresses, it will increase the local arterial blood supply and venous blood return, which can help to provide more energy, nutrition and electrolyte support and promote the recovery, and after the increase of venous return, it can also help to metabolize the inflammatory metabolites, and the symptoms of chondromalacia patellae can be effectively relieved. Second, through the hot compress, can effectively let the patellar tendon and the surrounding soft tissue become loose, avoid the accumulation of local metabolites, the symptoms can also be reduced. In the hot compress, try to choose warm water bag or fried hot coarse salt, each hot compress 20-30 minutes, about 5 times a day, and in the hot compress try to avoid the use of hot towel hot compress, because the hot towel with the evaporation of water, may lead to the knee joints again appeared to be cold.