[en] The main aim of the present experimental investigation is to study the dosimetric energy response of CaSO4: Dy thermoluminescence dosimeter to alpha particles. For proper estimation of the dose absorbed by the dosimeter, the alpha particle fluence must be measured. In order to do so, CR-39 plastic track detector is used. Experimental results indicated that CaSO4: Dy dosimetrie response to alpha particle is not only function to the alpha particle energy but also to the emission rate of the source