This is a review of fundamental and clinical research of near infrared(NIR) light therapeutic effects. NIR light represents a noninvasive therapeutic intervention without any side-effects. Research demonstrates that NIR light treatment stimulates mitochondrial oxidative metabolism in vitro, and accelerates cell and tissue repair in vivo. There are many clinical studies that show NIR can alleviate pain, diminish inflammation and speed up wound healing. NIR has a broad usage in wound healing and aging symptoms like neck pain, back pain, and arthritis. Additionally, NIR has good effects on diabetic foot ulcers.