In the present research, the filaments of Scytosiphon lomentaria collected from the northern coastal area (Yantai, Qingdao) and the southern coastal area (Zhoushan, Wenzhou)of China, respectively, were used as the experimental materials. The effects of different light intensity [7.2, 21.6, 36.0, 50.4, 64.8, 86.4, 108.0 and 129.6 μmol/(m²·s)] and different photoperiod (8L:16D, 10L:14D, 12L:12D, 14L:10D and 16L:8D) on the growth and development of filaments of the northern S. Lomentaria(Yantai and Qingdao) and the southern S. lomentaria (Zhoushan and Wenzhou) were studied by means of isolation and culture, mainly to find out the differences among them. Results indicated that: (1) Light intensity had significant influences on the growth of filaments of S. lomentaria, neither higher light intensity [≥108.0 μmol/(m²·s)] nor lower light intensity [≤21.6 μmol/(m²·s)] were suitable for the rapid growth of filaments; (2) Cultured for 20d, the increasing ratio of filament biomass and daily average growth rate of filaments of the northern and the southern S. lomentaria had reached the maximum under the condition of 64.8 μmol/(m²·s); (3) The optimum light intensity on the development of filaments of the northern and the southern S. lomentaria was 36.0 μmol/(m²·s), and cultured for 20 d, the sporangial branchlets ratio of filaments of S. lomentaria collected from Yantai, Qingdao, Zhoushan and Wenzhou had reached the maximum under the condition of 36.0 μmol/(m²·s), and the values were 34.72%±0.91%, 35.06%±1.17%, 35.37%±0.59% and 34.33%±0.41%, respectively; (4) Cultured for 20 d, the increasing ratio of filament biomass and daily average growth rate of filaments of the northern S. lomentaria had reached the maximum under the condition of 14L:10D, and the values were 82.75%±2.39%, 3.00%±0.36% and 81.28%±4.53%, 3.04%±0.49%, while the southern S. lomentaria had reached the maximum under the condition of 16L:8D, and the values were 89.52%±0.88%, 3.18%±0.30% and 88.66%±7.09%, 3.22%±0.26% respectively; (5) The appropriate photoperiod on the development of filaments of the northern S. lomentaria was 8L:16D-10L:14D, while the appropriate photoperiod on the development of filaments of the southern S. lomentaria was 10L:14D-12L:12D.