PURPOSE: To obtain a heat-sensitive smell producing microcapsule which can notify the temperature conditions even at a limited local point quickly and easily while selecting the temperature freely.

CONSTITUTION: The heat-sensitive smell producing microcapsule encapsules admixture of a smelling substance 1 and a thermally fusible composition 2 with a shell 3. The thermally fusible composition 2 begins to fuse at a specific temperature. When the volatile smelling substance 1 is previously admixed with the thermally fusible composition 2, the thermally fusible composition 2 begins to fuse when the atmospheric temperature exceeds the specific temperature and the smelling substance 1 evaporates. Fusing temperature can be altered easily by altering the composition of the thermally fusible composition 2. The shell 3 suppresses the evaporation of the smelling substance 1 effectively and preserves the smelling substance 1 for a long term until fusion of the thermally fusible composition 2. This constitution restricts the evaporation of the smelling substance 1 in short time even upon fusion of the thermally fusible composition 2.