An integrated investigation was carried out during late April to late May of 2014 in the coastal area of South Jiangsu Province to understand the early development of green tide in the Yellow Sea and discover the temporal and spatial distribution of green algal micro-propagules and macroalgae at the early stage of green tide. The results showed that green algal micro-propagules distributed in all stations from late April to late May, and micro-propagules of high density(> 300 ind. L~(-1)) concentrated in the adjacent Porphyra aquaculture area. Floating macroalgae were initially observed in the northern survey areas, and increased gradually. The dominant species was U. prolifera in the floating macroalgae, ranging between 90% and 100%. The seawater surface temperature and salinity in the above mentioned time period were suitable for the growth of macroalgae. This work can help government to strengthen management to reduce the blooms of macroalgae in the coastal area of South Jiangsu Province and also facilitate the decision-making for managers at the early stage of green tide. An integrated investigation was carried out during late April to late May of 2014 in the coastal area of ​​South Jiangsu Province to understand the early development of green tide in the Yellow Sea and discover the temporal and spatial distribution of green algal micro-propagules and macroalgae at the early stage of green tide. The results showed that green algal micro-propagules distributed in all stations from late April to late May, and micro-propagules of high density (> 300 ind. L ~ Porphyra aquaculture area. Floating macroalgae were initially observed in the northern survey areas, and increasing gradually. The dominant species was U. prolifera in the floating macroalgae, ranging between 90% and 100%. The seawater surface temperature and salinity in the above mentioned time period work suitable for the growth of macroalgae. This work can help government to strengthen management to reduce the blooms of macroalgae in the coastal area of ​​South Jiangsu Pro vince and also facilitate the decision-making for managers at the early stage of green tide.