Four times of investigation concerning phytoplankton and N- and P nutrients were carried out in twelve plantationaquaculture coupling ponds of mangrove in the Pearl River estuary. The results showed that single plantation or coupled plantation of four mangrove species 

Kandelia cande

Aegiceras corniculatum

Bruguiera gymnorrhiza

and

Rhizophora stylosa

 could purify DIN and PO

4

-P to a certain extent

but algal abundance was still in eutrophication or supereutrophication status in each pond. Using cluster and NMDS analyses

it was proved that mangrove could change the community structure

but it could not decrease the abundance and eutrophication of the algae in short period. The complex innermechanism relationship of mangrove with algae should be studied further.