Complementary and alternative medicine has been employed over thousands of years to relieve knee Osteoarthritis (OA) pain. Xinfeng Capsule, a patent Chinese herbal medicine, has been used in the treatment of Knee Osteoarthritis (KOA) Some studies involving animal subjects may explored its mechanism. However, presently, there is a lack of large-sample, multicenter, randomized, controlled trials to evaluate the effects of Xinfeng Capsule treated for KOA. Therefore, the investigators designed a randomized, placebo-controlled, double-blind, multicenter trial to evaluate the effectiveness and safety of Xinfeng Capsule in the treatment of KOA.

Inclusion Criteria:

• Participants must meet the American College of Rheumatology (ACR) 1995 revised criteria for KOA.
• Participants must be aged between 40 and 75 years.
• Participants shall not take non-steroidal anti-inflammatory drugs (NSAIDs) or corticosteroids during the 7 days prior to screening.
• Participants shall not take Chinese medicine for the treatment of KOA during the 7 days prior to screening.
• Joint function in the I-III, X-ray stage in the I-III.
• All participants shall agree to participate in the study and sign an informed consent form.

Exclusion Criteria:

• Patients whose joint clearance is significantly narrow or joint bone bridge connection is formed between a bony rigidity.
• Patients who have knee cancer, rheumatoid arthritis, tuberculosis, acute purulent or intra-articular fractures.
• Persons have obvious inside and outside of the knee varus deformity and a history of limb vascular nerve injury .
• Patients with severe cardiovascular, brain, lung, liver, kidney, or hematopoietic diseases.
• Pregnant women or breastfeeding mothers or individuals with known psychiatric disorders.
• Patients who are hypersensitive to the trial medication.