本研究目的在於了解網球發球揮拍擊球過程中，三種不同之擊球方式（平擊式發球、側旋式發球、上旋式發球）揮擊時拍頭的軌跡、變化，並比較其拋球拉拍及揮拍擊球時其拍頭軌跡之差異。受試者為國家級（A 級）網球教練一名，年齡為34歲，身高為179公分，球齡為26年，右手持拍。受試者向同一目標發球區發球，每種發球方式皆發十球，手筆記錄受測者每次發球有致或無故。測試時將每球揮擊之球拍影像傳入電腦分析，去除無效之發球，使用有效發球進行分析研究，依照數位影像與比例尺轉換出尺寸並訂出空間座標，依每畫格0.02秒為一畫面取標誌點並製作軌跡圖與重疊影像圖，計算出運動學參數，位移、速度與加速度等參數，得到運動學參數、空間模型與軌跡變化圈。結果發現：一、隨著擊球方式的不同，拋球及擊球的位置也會改變。在拉拍動作之預備動作至後舉抓背動作中，三種發球方式之差異並不明顯，但延續至拋球動作後，三種發球方式隨即有了改變。平擊式發球之拉拍動作所做球拍軌跡圓弧為最小；側旋式發球之球拍軌跡圓弧為最大，其拋球點之不同為一主要原因。在揮擊動作完整結束後，三種發球方式之收拍動作位置並無明顯差異。二、拋球時之拋球高度及拋球位置等因素需控制得宜，否則便無法將力量集中於一最理想之擊球點而發出理想之發球。三、要發出強而有力之發球，需要利用膝蓋之彈性，藉由腹肌、膝蓋、手腕三個部分共同來完成，擊球時手肘的彎曲也是絕對需要的一部份。

　　The purpose of this study was to investigate the analysis between three kinds of different tennis serving motions (flat serve, slice serve and kick serve) . The right-handed male is a Taiwan national tennis coach, who is 34 years old, 179 centimeters tall, and also he has been playing tennis for 26 years. He served 10 times for the same target by three kinds of serving; the effective and ineffective serves were recorded. Computer analyzed each serve of image, the effective serve were analyzed and the ineffective serves were deleted. According the digital image data and engineer's scale data transfer to the dimension, and conclude the coordinate. Every block was 0.02 second and found the data to make into the coordinate of track and the image of overlap, to calculate the data of kinetics, movement, speed and acceleration. These data were be used to make into the coordinate of kinetic data, the model of space and the picture of changing track. The result showed that the positions of hitting were changing between three kinds of different tennis serving motions. Although the differences were not so clear from the hands up motion to the back-scratch motion, the tracks of the different kinds of tennis serving motions were changing after the toss motion. The swing motion of flat serve was the smallest and the slice serve was the biggest due to the hitting point of toss up. The positions of swing down motion were almost the same after the follow-through motion. The height and the position of the toss were very important to powerful serve. It needs the resilience of knee, abdomen and wrist to serve powerfully, and also the curve of elbow was very important.