Body length, body width, fresh body weight and fresh-dry ratio were monthly measured in 10 varieties/lines of kelp Saccharina japonica with initial body length of (20.34±0.49) cm, initial body width of (3.21±0.16) cm, and initial fresh body weight of (0.05±0.01) g, including ‘Allen Bay’, ‘205’ and ‘Fengbao’, cultured at a density of 30 individuals per rope in 2 ropes per strain/line in Sanggou Bay(North latitude 37°09′56″ and East longitude 122°35′05″), Weihai, China to explore the superior and suitable varieties/lines of kelp in Sanggou Bay, Weihai. The results showed that the ‘Allen Bay’, ‘205’ and ‘Fengbao’ had good growth, and thus suitable for breeding, with the maximal body length of 320.93 cm in ‘Fengbao’, the maximal body width of 49.93 cm in ‘Ellen Bay’, the maximal body weight of 1.78 kg in ‘205’, and the minimal fresh-dry ratio of 7.91 in‘Ellen Bay’. However, the ‘South Korea Strain’ had poor growth index, and was not chosen for breeding, without obvious growth advantage in other varieties/lines. It can be concluded that different varieties/lines of kelps with differences in the growth are involved not only in species specificity, but also in the characteristics of the sea area, such as temperature and nutrient salts, ‘Allen Bay’, ‘205’ and ‘Fengbao’ being suitable culture in sea areas of Sanggou Bay.