Abstract: Reaction of Sansevieria trifasciata plant to formaldehyde pollution in a closed container was studied.Various formaldehyde concentrations were applied and the corresponding protective enzyme activities in the S.trifasciata plant determined.The results showed that at formaldehyde concentration of 0.347 mgm-3,0.431 mgm-3,0.543 mgm-3,0.672 mgm-3 and 0.884 mgm-3,the absorption rates of formaldehyde by the plant was 14.98%,20.64%,30.76%,39.43% and 45.14%,respectively.No significant correlation between the formaldehyde concentration in the container and that in the plant were found.On the other hand,the formaldehyde content in the plant varied with treatment time.The protective enzyme(i.e.,POD,SOD and CAT) activities in the plant showed no significant difference,when the formaldehyde concentration was varied.The results suggested that the formaldehyde absorbed by S.trifasciata did not accumulate in the plant,leaving no significant residual effects on it.