We studied on the “acellular mineral deposition” preceding bone induction by bone matrix gelatin (BMG). It was thought that “acellular mineral deposition” was formed by accumulation of calcium and phosphate without osteogenic cells and matrix vesicles, and may be significant for differentiation of osteoblast. Several new methods were developed to study “acellular mineral deposition”. New bone, uncalcified BMG and cartilage could easily be distinguished by differences in their staining intensities with hematoxylin and eosin. Calcified areas of epoxy sections could be stained with alizarin red S by heating and drying at 120°C. Toluidine blue, basic fuchsin and methylene blue, and various other stains were used for the study of bone induction in epoxy sections. Simple methods involving electron probe X-ray microanalysis, electron diffraction and Fourier transform infrared spectroscopy (FT-IR) were developed for the analysis of minerals in sections prepared for histological observation.