This study investigated the relationship between critical velocity (CV) and the swimmer's achievements, and compared the LA of four swimming styles with their CV results. Thirteen athletes (11 boys, 2 girls, 17.56±2.lyr; 60.53±7.92kg; 171.35±6.61cm) were administered to a test which required them to perform 50m, l00m and 200m of four styles in order to take down their CV results, and based on these results, to calculate the CV results for 400m of each style. And the physiological data of LA were recorded after each test. The Pearson product-moment correlation and repeated measures were used to analyze the data. The test result shows that the athletes' final achievements and their CV results were closely related: the further the distance, the closer the coefficient. Therefore, the CV results can be used for studying the endurance of every swimming style. And no significant difference is found between the CV and the LA among all the swimming styles. This reveals that the CV of different styles possesses an unanimity blood-lactate reaction. It is concluded that the CV result can be considered as a setup for training in order to obtain a sound effect on exercise intensity.