The M X-ray spectra of Ta induced by H+, He2+, Ar11+ and Xe20+ are measured in Heavy Ion Research Facility in Lanzhou. The intensities of M (M3N5) and N (M4,5N6,7), i.e. I and I, are also derived from the spectra. It is found that the intensity ratio of I/I increases with the increase of projectile atomic number. The results show that the M3-subshell fluorescence yield 3 of Ta target is greatly enhanced, owing to multiple ionization effect in collision with heavy ions.