Abstract: The effect of short period of photorespiration inhibition by 2% O₂ air environment on PS I and PS II of Zelkova schneideriana tree species was measured by technologies of chlorophyll fluorescence and leaf absorbance change of 820 nm spectrum by the leaves. The results showed that both the PS structure and functions were changed, the activities of PS and electron flowing direction inside were affected by the temporary photorespiration restriction. The primary photo energy transferring efficiency and potential activities of both PS I and PS II, Ft and ETR indices decreased, whereas q_P and q_N fluorescence parameters increased when air environment of 2% O₂ concentration was applied.