Abstract: In order to determine the effect of cadmium on the physiological changes of Clerodendrum bungei seedlings，field experiment was conducted with 5 Cd concentrations as 0，0.1，0.3，0.6，0.9 mmol/L. Based on chlorophyll fluorescence parameters，malondialdehyde（MDA） content，proline content，soluble sugar content and soluble protein content measarements. The results showed that potential photochemical efficiency（Fv/Fo） and chemical quenching coefficient（qP） declined with Cd2+ concentration increased，the highest rate of inhibition was 43.10% and 37.82%，while non-photochemical quenching coefficient（ qN） gradually increased by 48.13%. Low concentration Cd2+ had promotion effect on the contents of soluble sugar and soluble protein，but high concentration of Cd2+ had an significant inhibitory effect. With the Cd2+ stress concentration increased，the contents of MDA and proline in leaves of Clerodendrum bungei increased by 39.01%，73.07%. MDA content changed significantly at high concentration，which increased up to 45.29%. There results suggested that the plant might somewhat adapt to cadmium stress，by adjusting its own the photosynthetic characteristics and osmatic adjustment substance.