Abstract: Good appearance is the basic condition to play a role in landscape function for urban water． However，the appearance of enclosed landscape water is in serious pollution now． This paper conducted about half a year’s observation and water quality monitoring in the enclosed water located in Shitao Garden． The course of apparent pollution was described by absorption spectrometry． Meanwhile the correlations of sensation pollution index ( SPI ) and environmental factors were analyzed to study the apparent pollution mechanism． The apparent pollution in enclosed water varied markedly with the season． SPI had a significant positive correlation with temperature，turbidity，UV254 ，Chl-a and a negative correlation with DO． The correlation coefficients were 0. 786， 0. 951， 0. 595， 0. 849，－ 0. 699，respectively． The decomposition of plant residues and the competitive growth of algae and duckweed would result in the anormaly of color and turbidity，and even the serious apparent pollution with black-odor phenomenon．