目的：打擊在棒球比賽中為重要的得分技巧，選手透過打擊練習來增進打擊能力。打擊練習常見的為投手投球及發球機發球，但投手在不斷的投擲過程中容易受傷，發球機便成為打擊練習有利的輔助器材。常見的發球機臺為揮臂式及滾輪式，但無從得知不同類型發球機臺的發球落點與速度穩定性之差異。本研究目的為探討三台不同機型的發球機發球落點及速度穩定性，希望能提供不同形式發球機臺落點及速度穩定性之參數，做為日後選用之參考。方法：發球機臺使用揮臂式發球機、美製及台製雙滾輪發球機，以相同一批光滑無縫線球體作為測試用球以同一速度進行測試，以光閘收取速度，並利用塑膠瓦楞板標記落點。以單因子變異數分析機臺間落點距離與速度之差異。結果：在發球機落點位置精準度之比較上，美製雙滾輪及台製雙滾輪顯著優於揮臂式發球機；在光閘速度穩定性之比較揮臂式發球機及台製雙滾輪發球機優於美製雙滾輪發球機。結論：美製及台製雙滾輪發球機發球落點位置有較好的精準度分佈；揮臂式發球機及台製雙滾輪發球機則是有較好的速度穩定性，在綜合以上落點及速度穩定性後發現，台製雙滾輪發球機有較良好的落點位置精準度及速度穩定性。

Purpose： Batting in baseball is an important skill for the scores, and the players do the batting practice to enhance their batting ability. The pitcher and pitching machines are both two of common practice type, and the pitcher was easily injured because of repetitive pitching. Therefore, pitching machines become good auxiliary equipment in batting practice. In currently, swing arm type pitching machines and double roller ball machine are two common training baseball pitching machine, but not privy to difference in impact point placement precision and speed between different types of pitching machines. The purpose of this study was to investigate the stability of the pitching machine three different of impact point placement precision and speed stability. It able provide different pitching machine of impact point placement precision and speed stability parameters, as the future used to choice pitching machine of reference. Methods: To use swing arm type pitching machines, American made and Taiwan made double roller pitching machine test impact point placement precision and speed stability. The same smooth seamless ball and same rate as for testing. The light gate would be used to measure speed and use of plastic corrugated board marker impact point. The one-way analysis of variance was used to test impact point placement precision and speed stability difference between each pitching machine. Results: The results showed that impact point placement precision was significantly better in American made double roller pitching machine and Taiwan made double roller pitching machine than that in the swing arm type pitching machines. The light gate speed stability showed that the swing arm pitching machines and Taiwan made double roller pitching machine was significantly better than the American made double roller. Conclusion: In terms of impact point placement precision, American made double roller and Taiwan made double roller pitching machine pitching location was excellent. The swing arm pitching machines and Taiwan made double roller pitching machine have better speed stability than American made double roller. Comprehensive above, Taiwan made double roller pitching machine show relatively good impact point placement precision and speed performance.