Electronic stethoscope system is the most frequently used approach to collect respiratory sound to evaluate the lung function of patients or investigate various kinds of lung diseases of in recent years. However, current electronic stethoscope systems are just suitable for measuring respiratory sounds under static state. Under motion, the respiratory sounds are easily affected by the vibration of the human body. Moreover, it is also inconvenient to wear the conventional electronic stethoscope system. In order to improve the above issues, a novel wireless respiratory sound recording system was proposed to collect respiratory sound under motion. Here, a wireless and wearable respiratory sound recording device was designed to collect respiratory sound wirelessly. It is also easy to wear and monitor respiratory sound under motion due to its advantages of small volume and wireless transmission. Moreover, the technique of adaptive filter was also applied to enhance the noisy respiratory sound from single channel trial. From the experimental results, the noisy respiratory sound can be effectively improved by the proposed adaptive filter. Therefore, the proposed system exactly contains the potential of being a good assisting tool for lung diseases and may be applied in the applications of lung and sports medicine in the future.