A method for judging a coercive force of a magnetic recording medium, so recording magnetic information can be formed in either a low coercivity magnetic medium or a high coercivity magnetic medium by using a magnetic head. A magnetic information recording step writes magnetic information in the magnetic recording medium by alternately using a first write current suitable for writing in the low coercivity magnetic medium and a second write current suitable for writing in the high coercivity magnetic medium. A magnetic information reproducing step reproduces the magnetic information written in the magnetic recording medium. A judging step makes a judgment on a coercive force of the magnetic recording medium by way of comparing a first reproduced output A of the magnetic information written with the first write current and a second reproduced output B of the magnetic information written with the second write current.