We present results of an extensive search for weak-line T Tauri stars (WTTS) in the outskirts of the Taurus-Auriga molecular cloud on the basis of the ROSAT All-Sky Survey Bright Source Catalog. Our surveyed region extends from 2 h 40 m to 5 h 40 m in right ascension and from 10 • to 40 • in declination, with the central part of Taurus-Auriga (4 h < α < 5 h , 15 • < δ < 34 • ), accomplished by Wichmann et al. (1996) , excluded. Within a sky coverage of about 10 3 square degrees, 219 X-ray

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... s fulfil the criteria for selecting program sources suggested by Neuhäuser et al. (1995a) , and 164 of these X-ray sources were found to have at least one optical counterpart with E magnitude brighter than 16. Low-resolution spectroscopic observation has been carried out in order to discard early type stars and galaxies from the sample, additional intermediate-resolution spectra of a sub-sample of 156 late type optical counterparts were obtained for spectral classification and for the calculation of the equivalent width of H α emission and LiI line absorption at 6707Å. Excluding 2 previously identified WTTS, a total of 75 new candidate WTTS and one possible classical T Tauri star have been discovered in our study. The majority of the newly found Li-rich optical counterparts are believed to be PMS stars rather than ZAMS stars as those of the Pleiades.