Multiwalled carbon nanotubes (MWNTs) with high quality were prepared by DC arc discharge of pure graphite electrodes in hydrogen gas. Because these MWNTs co-existed with few carbon nanoparticles compared with the usual MWNTs prepared in helium gas, their purification could also easily be done by infrared irradiation in air at 500°C for 30min. Resonance Raman spectra of purified MWNTs were measured, and breathing modes at about 500cm−1 corresponding to a very thin central hole of about 5Å diameter were found. A new peak at about 1840cm−1 appeared for pristine MWNTs, and its intensity strongly depended on the preparation conditions (pressure of hydrogen gas). The measurement of temperature dependence for electric resistance of MWNTs showed metallic or semiconducting tendency. Purified MWNTs could be used as bright and long-life field emitters for cathode ray tubes, and a desirable current density of 1mA/cm2 could be stably achieved at a field of 1.2V/μm.