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We previously built a sample of 14,012 extremely variable quasars (EVQs)based on SDSS and Pan-STARRS1 photometric observations. In this work we presentthe spectral fitting to their SDSS spectra, and study the spectral variation in1,259 EVQs with multi-epoch SDSS spectra (after prudently excluding spectrawith potentially unreliable spectroscopic photometry). We find clear"bluer-when-brighter" trend in EVQs, consistent with previous findings ofnormal quasars and AGNs. We detect significant intrinsic Baldwin effect (iBeff,i.e., smaller line EW at higher continuum flux in individual AGNs) in the broadMgII and CIV lines of EVQs. Meanwhile, no systematical iBeff is found for thebroad Hb line, which could be attributed to strong host contamination at longerwavelengths. Remarkably, by comparing the iBeff slope of EVQs with archivedchanging-look quasars (CLQs), we show that the CLQs identified in literatureare mostly likely a biased (due to its definition) sub-population of EVQs,rather than a distinct population of quasars. We also found no significantbroad line breathing of either Hb, MgII or CIV, suggesting the broad linebreathing in quasars may disappear at longer timescales ($\sim$ 3000 days).

Extreme Variability Quasars in Their Various States. II: Spectral Variation Revealed with Multi-epoch Spectra