In order to explore the comparation of injury on leaf adaxial and abaxial sides in Hosta plantaginea induced by ozone, micro-observation, chlorophyll fluorescent, gas exchange characteristics and chlorophyll content were studied in H. plantaginea seedlings under various ozone levels. Our micro-observation showed that injury symptoms on leaf adaxial side were induced by 10 days ozone treatment (200 μg·kg⁻¹), however, the injury on leaf abaxial side was observed only when ozone concentration reached 300 μg·kg⁻¹. In the presence of ozone, the shapes of polyphasic rise of fluorescence transient both in the two sides were greatly changed. Further analysis revealed that ozone induced pronounced K, J and I steps both on adaxial and abaxial sides of H. plantaginea leaves. Moreover, the enhancement of K step on adaxial side was more significant than that on abaxial side. Additionally, we also noticed that ozone induced the decrease in photosynthetic rate and chlorophyll content, while REC and MDA increase under various ozone treatments. According to micro-observation and the polyphasic rise of fluorescence transient, we thought that ozone can injure the both side of H. plantaginea leaves. The potential mechanisms were also discussed in this study.