The new varieties of "Shenfu No. 1" and "Shenfu No. 2" and the traditional cultivar of Pyropia haitanensis were cultivated at the same sea for testing their high-temperature-resistance in the study. The results showed that the blades of the traditional cultivar rotted away due to the water temperature higher by 1 to 2℃ as compared to that of the normal year after cultivation of P. haitanensis at sea. However, the varieties "Shenfu No. 1" and "Shenfu No. 2" maintained the normal color and morphology of blades and higher growth rate, and good yield and quality, even if cultivated at the same sea area. The results indicated that the new varieties "Shenfu No.1" and " Shenfu No.2" had the advantages of high-temperature-resistance and higher growth speed than the traditional cultivar. The new varieties "Shenfu No. 1" and "Shenfu No.2" had a great potential to be used as a substitute for the traditional cultivar in the future.