Abstract: Sargassum horneri is one of the main components in the subtidal seaweed flora along the Chinese warmer water coast. Artificial cultivation trials of the subtidal brown alga S.horneri at Nanji islands from October 2007 to May 2008 were reported. The results revealed that the vegetative growth of the individuals was well at temperature from 7.1 to 20.5 ℃. Maximal average daily increase of fresh weight and length were 81 g and 18 cm, respectively. After the farming period of 190 d, the average fresh weight and length of farmed individuals were 5.3 kg and 8 m with the maximal fresh weight and length of 12.3 kg and 13.2 cm, respectively.