The air pollution stress around the thermal power plant lead to the significant reduction in size and biomass of root and shoot, photosynthetic rate, stomatal conductance, intercellular CO2 concentration, photosynthetic pigments and photosynthetic area of  Croton bonplandianum. The resulting stresses of air pollution and reduced foliage further affected the over all morphology and physiology of the plant. Root biomass and chlorophyll a showed maximum reduction than any other selected parameters studied in the stressed area. Chlorophyll a was found to be four and half times more sensitive to air pollutants than carotenoids. Key words:  Air pollution; Thermal power plant; Morphology and physiology; C. bonplandianumDOI: 10.3126/eco.v17i0.4103Ecoprint An International Journal of Ecology Vol. 17, 2010 Page: 35-41 Uploaded date: 29 December, 2010