To provide a method of evaluating cracking in a ground by grout capable of accurately evaluating the filled state of the grout into the cracking in the ground to be improved without being affected by the cutting of a hole wall surface by a bit when a hole to be bored is drilled, abrasion by flushing air (cutting article), and washing by excavating water.

In this method of evaluating cracking in a ground by grout filled in the ground through the hole to be bored formed in a rock (ground) to be improved, using a fluorescent grout mixed with a fluorescent substance, a core boring 12 is performed at a portion separating from a bored hole 11 in the rock 10 to be improved in which the fluorescent grout is filled and a core 13 is sampled, a light emitting beam corresponding to the fluorescent substance is radiated from a light emitting source 15 to the sampled core 13, and an image obtained by photographing the outer peripheral surface of the core 13 from which the fluorescent substance emits fluorescent light is image-processed. Consequently, the filled state of the grout into cracking 14 in the rock 10 to be improved and the state of the cracking 14 in the rock 10 can be evaluated.