We have obtained optical intermediate resolution spectra ( R = 3000 ) of the narrow-line quasars DMS 0059 - 0055 and PG 1543+489 .
The [ O iii ] emission line in DMS 0059 - 0055 is blueshifted by 880 km s ^ { -1 } relative to H \beta .
We also confirm that the [ O iii ] emission line in PG 1543+489 has a relative blueshift of 1150 km s ^ { -1 } .
These two narrow-line quasars show the largest [ O iii ] blueshifts known to date among type 1 active galactic nuclei ( AGNs ) .
The [ O iii ] emission lines in both objects are broad ( 1000 – 2000 km s ^ { -1 } ) and those in DMS 0059 - 0055 show strong blue asymmetry .
We interpret the large blueshift and the profile of the [ O iii ] lines as the result of an outflow interacting with circumnuclear gas .
Among type 1 AGNs with large blueshifted [ O iii ] , there is no correlation between the Eddington ratios and the amount of [ O iii ] blueshifts .
Combining our new data with published results , we confirm that the Eddington ratios of the such AGNs are the highest among AGNs with the same black hole masses .
These facts suggest that the Eddington ratio is a necessary condition or the [ O iii ] blueshifts weakly depend on the Eddington ratio .
Our new sample suggests that there are possible necessary conditions to produce an outflow besides a high Eddington ratio : large black hole mass ( > 10 ^ { 7 } M _ { \sun } ) or high mass accretion rate ( > 2 M _ { \sun } /yr ) or large luminosity ( \lambda L _ { \lambda } ( 5100 { \AA } ) > 10 ^ { 44.6 } erg s ^ { -1 } ) .