本研究主要目的在分析軟式網球拍大、小拍面及不同網線張力對於碰撞後彈性恢復係數的影響。實驗是將網球拍固定在虎頭鉗鮫上，調整網球發球機所射出之球與網球拍做正面垂直碰撞，透過 Nac 高速攝影機 (每秒 1000 張) 將整個實驗過程拍攝，影帶經過 Peak Performance軟體系統進行數位化處理，將資料分析後，獲得之結論為： 1.網球拍拍面大小對於彈性恢復係數 (COR) 有顯著的影響。大拍面比小拍面可獲得較高碰撞後彈性恢復係數。 2.在同一拍面的軟式網球拍中，受不同網線張力的影響下，穿上 40磅的拍線有較高的彈性恢復係數。

　　　　　The purpose of this study was to investigate the effect of racket size and string tension on the coefficient of restitution (COR) for soft tennis rackets. In order to get accurate results, the racket was fixed with the clamp and the tennis ball was controlled to impact the racket vertically. The whole experimental procedure was filmed by Nac high speed camera at the rate of 1000 frames per second. Using the Perk Performance System, the video tape was digitized, and the data were then analyzed with two-way ANOVA .The results were summarized as followed: The influences of the racket size to the coefficient of restitution (COR) are significant. The higher value of COR is obtained for the over-size racket than that of the small size racket. As the racket size is fixed, the value of COR depends with the parameter of string tension, and experiments shows that the case of 40 pounds has the hi COR than the other two.