This invention relates to a method of measuring a rheological property of a composite filled with particles, and evaluation equipment, in which in situ measurement is performed of the rheological property of a composite filled with particles obtained by mixing a particulate material as raw material with a liquid material, in a condition with the original material structure maintained, without destroying the material by applying external force such as shearing force thereto, comprising a step of measuring the coagulation structure of the particulate material within the composite filled with particles as an anisotropy signal, and a step of employing the amount of this anisotropy as an index of the rheological property value of the composite.