. NO3-N concentration of microcosm water decreased sharply from 1.90 mg/L at first to 0.02 mg/L, whereas NH4-N concentration increased from 0.03 mg/L to 2.85 mg/L continually. PO4-P concentration was 0.03 mg/L at first and increased to 2.39 mg/L by decomposition. Therefore, available phosphorus seems to have leached with higher rate than nitrogen from the petals litter. Increase about 0.02 mg/L in PO4-P concentration could be estimated in artificial pond from the calculation on the total quantity of fallen blossoms. This result suggests that available phosphorus from the decomposed Prunus petals could cause eutrophication in the artificial pond.Key words : Decey rate, Eutrophication, Petal, Phosphate dynamics 서 론연못은 2 m 이하의 수심 또는 8 ha 이내의 면적을 보이 †