****************************************************** PR # 41163 ASCA has observed several high-z radio-loud quasars, and obtained good quality spectra of these objects (e.g. Siebert et al. 1995, Cappi et al. 1995). However, no spectral information is available so far for the high-z radio-quiet quasars. We propose to observe 3 X-ray selected high-z (z>2) radio-quiet quasars in order to fill this gap. The scientific goals of the proposal are: i) provide good constraints on the spectral parameters (Nh, photon index and FeK line parameters) of the quasars and ii) compare these results with those obtained for low-z radio-quiet quasars and (high-z and low-z) radio-loud quasars. ******************************************************