Objective:To investigate the relationship between subchondral bone marrow lesions and articular cartilage injuries in early knee osteoarthritis (OA) patients. MethodsThe knee joints of 67 patients with early knee osteoarthritis (OA group) and 22 healthy volunteers (healthy group) were enrolled for magnetic resonance imaging (MRI) scanning, and T2 values of knee cartilage in different regions were measured by T2 mapping sequence. In OA group, the whole organ magnetic resonance imaging score (WORMS) was used to evaluate the subchondral bone marrow lesions (BMLs) in different regions. The difference of cartilage T2 values in different regions was compared, and the correlation between cartilage T2 values in different regions and BMLs scores in corresponding regions was analyzed.  Results:①In OA group, 41.77% of the patients were within K-L grade I and 58.20% in K-L grade Ⅱ. There was no significant difference in body mass and BMI between the two groups (P>0.05). ②The T2 values of patellar cartilage and femoral cartilage in OA group were significantly higher than those in healthy group (P<0.05). ③Patients with early knee osteoarthritis were often accompanied by different degrees of cartilage injuries and osteophyte formation with high incidences of subchondral bone marrow lesions and meniscus injuries, accounting for 86.4% and 84.8% respectively. It is suggested that the pathological change of early knee osteoarthritis is the degeneration of total knee joints including cartilage, subchondral bone, and meniscus, etc. ④WORMS scores of BMLs in medial and lateral femoral condyle and medial and lateral tibial plateau of patients with early knee osteoarthritis were positively correlated with T2 values of cartilage in corresponding regions (P<0.05).  Conclusion:Femoral and patellar cartilages of patients with early knee osteoarthritis have degeneration to varying degrees. The larger the BMLs range in tibial plateau and femoral condyle region, the more severe the cartilage injuries in the corresponding region.