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For most bright nearby AGN, we commonly detect He-like O VII emission lines at ∼ 0.56 keV. In this work, I study the correlation between the O VII emission line strength and the instantaneous AGN ionizing luminosity (13.6 eV − 13.6 keV) in a sample of bright nearby AGN to understand the effect of L ion on the emission lines. I find two interesting results: 1. There is no significant correlation between O VII emission line normalization and L ion. 2. There is no strong emission line for very bright AGN (log L ion ≥ 45 erg s −1). The first result implies that there are several other physical factors apart from L ion that impact the emission line strength, such as the cloud density, and its distance from the central source. The second result may imply that a high luminosity AGN have blown off most of the material in its vicinity and the clouds that are emitting the emission lines are located further out, receiving less radiation and hence weak.