Objective To investigate the values of quantitative parameters of T2 map of cartilage in different ARCO stage of the femoral head necrosis. Methods Different Arco stage avascular necrosis of the femoral head (ARCO I, ARCOII, ARCOIII period) and normal femoral head with 20 cases in each were enrolled in this study from age 20 to50, all case of illness all MRI check. Data quantitative calculation of each period of femoral head necrosis and normal cartilage of femoral head T2 map value. All the selected necrosis and normal subjects were excluded on the basis of observation of disease osteoporosis and other effects. Results Along with the progress of the disease, avascular necrosis of the femoral head ARCO stage is high, the more serious illness, cartilage T2 map value higher, cartilage damage and also more obvious.The LSD test analysis showed that between avascular necrosis of the femoral head ARCOIII period cartilage and normal femoral head, ARCOI, ARCOII period cartilage T2 map values had significant difference, P values less than 0.05. Conclusion Normal T2 map values of the cartilage of the femoral head can be defined as about (49.39±8.158), the clinical possibility can be the interval value as the reference standard, as with the progress of the ARCO I-III, the extent of the femoral head cartilage damage degeneration has a gradually increasing trend.