This is a randomized, double-blind study to compare the efficacy and safety of LAYLA tablet and Joins tablet in the treatment of osteoarthritis of the knee.

Inclusion Criteria:

• Patients ≥40 and ≤ 80years of age
• Radiographic evidence of grade 2 or 3 osteoarthritis based on the Kellgren & Lawrene radiographic entry criteria
• Stable osteoarthritis during 3 months
• Score of 100mm pain VAS ≤ 80mm at screening
• Score of 100mm pain VAS ≥ 50mm at baseline
• Written consent form voluntarily

Exclusion Criteria:

• Disease of spine or other Lower limb joints that could affect to evaluate the efficacy
• History of surgery or arthroscopy of the study joint within 6 months
• Trauma of study joint within 12 months
• Medication of constantly(more than 1 week) corticosteroid by oral within 3 months
• Medication of intra-articular injection within 3 months
• Diagnosed with psychical disorder, and taking medication
• History of upper gastrointestinal ulceration within 6 months
• History of upper gastrointestinal bleeding within 12 months
• Serum creatinine, ALT, AST, total bilirubin over UNL X 2.0 at screening test
• History of hypersensitivity to LAYLA, JOINS, or NSAIDs
• Participation in another clinical trials within 4 weeks
• Medication of constantly (more than 1 week) narcotic analgesics within 3 months
• Not consent about using effectual contraception method during trial
• Pregnant or lactating woman
• Investigator's judgment