Observations of the C iv and Mg ii absorption lines in the Seyfert 1 galaxy NGC 4151 obtained with the GHRS in October 1994 are presented .
The data from the STScI archive show multiple broad and narrow components in both species .
In addition to Galactic absorption , four narrow and four broad systems associated with NGC 4151 are identified .
Two broad systems dominate the total equivalent width , and their mean blueshift and width are comparable to the broad Lyman line and continuum absorption seen in far-UV spectra from the Hopkins Ultraviolet Telescope .
Narrow-line C iv emission is present on the red side of the broadest absorption trough , and narrow absorption at the systemic velocity of NGC 4151 , presumably in its own ISM , absorbs the core of the narrow emission line .
Strong Mg ii absorption is present in all but two velocity systems .
Ratios relative to the corresponding C iv components suggest a low ionization parameter for the absorbing gas : U \sim 1 - 3 \times 10 ^ { -3 } .
This makes none of the identified UV absorption systems a good candidate for association with the warm X-ray absorbing gas .