As a traditional Chinese health and fitness Qigong exercise routine, Ba Duan Jin, or Eight-section Exercises, dates back to the Song Dynasty(960-1279).With easy movements and impressive effects on the health, it is a gene in China's health and fitness culture. Ba Duan Jin is part of the New Health Qigong Exercise Series compiled and published by the Chinese Health Qigong Association. As a safe aerobic exercise, it features a movement intensity and format in line with the theories of kinetics and physiology. Added to the traditional eight movements, are sections on the preparatory posture and closing form, making the exercises more complete, standardized and rational. It has been proved that practice of Ba Duan Jin improves the respiratory system, limb strength, and flexibility of the joints, and fortifies the nerves, as well as enhances the general balance. It improves the cardiovascular function and helps to cure such illnesses as coronary artery scleroses and osteoporosis. It strengthens one's immune system to a degree, and delays the ageing process, so as to increase the life span. It also improves one's mental health. A survey shows most Ba Duan Jin practitioners are satisfied with the practice duration, intensity and routine format outlined below, and testify to Ba Duan Jin's effects on health improvement. Ba Duan Jin's characteristics:(1) Gentle,Slow,Smooth and Consistent. The movements should be gentle, relaxed and gracefully extending, on the basis of a well-balanced stance. They should be executed in a round and flowing way, with a distinction between substantial and insubstantial. The spine initiates movements throughout the body. Without any restraint, the routines are performed with a natural approach and well-coordinated movements of the upper and lower body at a suitable speed. The movements should be continuous, like flowing water or floating clouds, to instill calmness in the practitioner's body and mind. No interruption is allowed, even at the interplay of the substantial and insubstantial. This helps to smooth the internal circulation of vital energy and improve one's health and fitness. (2)Rhythmic Combination of Relaxation and Strength, and of Dynamism and Inertia. Relaxation requires a restraint-free state of the muscles, joints and central nervous system. Guided by the mind, the breathing should be gentle, with the heart calm and the body relaxed. But a correct stance and posture are essential to relaxation, which should be deepened from the exterior to the interior. Strength means the rational power required in the practice, between the end of the previous movement and the start of the next one. Such is the case with the hand movement in "Holding the Hands High with Palms up to Regulate the Internal Organs," the archer's horse stance in "Posing as an Archer Shooting Both Left-and Right-handed, "the one-arm lift in "Holding One Arm Aloft to Regulate the Functions of the Spleen and Stomach, "the head and hands movements in "Looking Backwards to Prevent Sickness and Strain, "the horse stance in "Swinging the Head and Lowering the Body to Relieve Stress," the hand movement in "Moving the Hands down the Back and Legs, and Touching the Feet to Strengthen the Kidneys," the fists thrust in" Thrusting the Fists and Making the Eyes Glare to Enhance Strength," and the head movement and retraction of the toes and buttocks in "Raising and Lowering the Heels to Cure Diseases." Dynamism and inertia are the outward expressions of bodily movements. Dynamism requires practitioners, guided by the mind, to execute movements in a flexible, vivid, consistent and natural manner. Inertia means that practitioners should be calm when strength is required between two movements, especially during the slow application of strength in the above-mentioned movements. An external pause does not interrupt the internal circulation, with the muscles still stretched. The stimulation of the intended parts of the body can be better achieved with rational strength for an extended period.(3)Combining Mind and Body to Cultivate Vital Energy.Mind in Qigong refers to one's mental state and normal consciousness, and bodily movements guided by the mind and thoughts. The two form an interactive and inter-promotional integrity, characterized by harmony and symmetry shown in all, and between every two, movements. Ba Duan Jin is noted for its smooth comfortable postures and its movements are performed with profound inner strength. With a concentrated mind followed by a vigorous body, it naturally combines firmness with gentleness, and exercises through the interplay of the substantial and the insubstantial.