Seasonal characteristics of algae composition and responses to its habitat in shallow subsidence pool as new wetland were discussed with a case study of Pan-san pool in Huainan city.The results showed that as new wetland,the shallow subsidence pool was seriously polluted in summer(CODCr of 52.63 mg/L,TP of 0.45 mg/L,TN of 2.01 mg/L) and its nutrient status was heavily trophic(dominant algae species of Cyanophyta).Meanwhile,in spring and fall,the shallow subsidence pool was lightly polluted and its nutrient status was medium trophic,but closed to heavily trophic(dominant algae species of Chlorophyta in the fall).Algae biomass in the shallow subsidence pool reached 27.54 mg/m3 in the fall(highest),5.82 mg/m3 in spring(lowest),16.85 mg/m3 in summer,respectively,and showed positive relationships with TP and TN,and significantly positive relationship with CODCr,indicating that algae biomass could be used to reflect the level of nutrient and organic pollutants.But there is not relationship between algae biomass and total rigidity in shallow subsidence pool,indicating that algae does not affect total rigidity heavily.It is interesting that negative relationships between algae biomass and water depth(H) showed that water quantity in shallow subsidence pool could change seasonal characteristics of algae.All got information can provide insights into water environment in shallow subsidence pool.