Abstract：In the freestyle (front crawl) swimming event, power is mainly generated through the competitors' stroke. Optimizing the relationship between the stroke length and stroke rate could help swimmers to increase their speed and maintain a consistent pace at different distances. Do swimmers' pacing strategies vary by skill level? The purpose of this study is to compare the pacing strategies used in the men's 400 m freestyle by the finalists of Taiwan's 2020 National Intercollegiate Athletic Games to those in the 2019 World Swimming Championships. Notational analysis was employed while examining videos of the finals, and the average speed, stroke length, stroke rate and normalized data were recorded for every 50 m section of the race. Results indicate that the interaction between level and distance revealed significant effects for both the average and normalized speed. Both international and national swimmers had the highest average speed in the first 50 m. Different strategies emerged at later lengths, however-international competitors displayed their slowest average speed and normalized speed at 150-200 m, while national swimmers did so at 250-300 m. At both skill levels, the stroke length and speed gradually decreased and the stroke rate increased. Despite this similarity, the average speed of international swimmers at any lap is significantly faster than that of national swimmers. In conclusion, the normalized data indicate that different pacing strategies were adopted by international swimmers and national swimmers, especially in the final 300-350 m. International swimmers are better than Taiwan's national-level swimmers in speed and stroke performance. (Full text)