To examine the reliability of the measuring method of the critical current density Jc induced by a pulsed magnetic field, we measured Jc of high-Tc superconductors. The main advantages of this method are that it is not needed to use any electric contact, and that the measuring time is relatively short. Sintered and single-crystal YBa₂Cu₃O_y, sintered YBa₂Cu₄O_y and sintered Bi systems were prepared. Jc of YBa₂Cu₃O_y single-crystal thin films are about 10⁶A/cm² at liquid nitrogen temperature. This value agrees with the Jc measured by the four terminal method. The results of sintered samples also show a reasonable temperature dependence.