  X-ray loud M dwarfs are a major source of by-product (contamination) in the
X-ray band of the multiwavelength quasar survey (MWQS). As a by-product, the
low dispersion spectra of 22 M dwarfs are obtained in which the spectra of 16
sources are taken for the first time. The spectral types and distance of the
sample are given based on spectral indices CaH2, CaH3, and TiO5. The parameter
{\zeta}TiO/CaH is calculated to make the metallicity class separation among
dwarfs, subdwarfs and extreme subdwarfs. We also discuss the distributions in
the diagrams of Log(Lx/Lbol) versus spectral type and infrared colors.
