Abstract: Seedling period is the key phase for Rhizophora stylosa population inhabit. An artificial nursing experiment of R. stylosa was conducted on Beihai beach. The results show that average height growth in the first year is 3.7 cm?month^-1. One-year seedling is divided into three phases by growth rates. July to October is the fast growth phase when the average temperature is 27.1℃ and growth rate is 6.75 cm?month^-1. In the slow growth phase of December to March, the growth rate is 0.9 cm/month and mean temperature is 16.3℃. During the medium growth phases of April to June and November, the growth rate is 3.76 cm?month^-1 while the mean temperature is 24.7℃. The growth characters of 3-year seedlings are that the seedling height growth is the fastest in the first year, and 2-year seedling biomass is 1.4 times more than the 1-year’s, the 3-year seedling biomass increase slows down and has increased only 24% compared to the 2-year’s.

Key words: Rhizophora stylosa seedling, biomass, growth character