Abstract: The seedlings of Vallisneria asiatica Miki L. were planted in the turbid water with different turbidities of 30NTU,60NTU and 90NTU which was caused by suspended substance. The growth of the seedlings of Vallisneria asiatica Miki L. ineach treatment was investigated. Photosystem II (PSⅡ)photochemical efficiency (Fv/ Fm ratio), actual photochemical efficiency (Yield), photochemical quenching (qP), non2photochemical quenching (qN), electron2transport rate (ETR) and rapid2lightcurves were measured by submersible, pulse2amplitude modulated (PAM)fluorometer: Diving2PAM. The result showed that inthe fifth day, survival,growth and photosynthesis of the seedlings of Vallisneria asiatica Miki L werenot influenced markedly(p>0.05),the seedlings of Vallisneria asiatica Miki L. protected PSⅡby increasing heat dissipating. Survival,growth and photosynthesis of the seedlings of Vallisneria asiatica Miki L were influenced markedly (p2·s, but 60NTU and 90NTU was only 17μmol quanta/ m2·s, all of these wereless than the control group which was 248μmol quanta/ m2·s.