The aim of the study is to calculate the alpha emitters in bone samples of some animals by counting the tracks of alpha particles emitted from radioactive nuclei (Pb-210, Po-210, Ra-226) using the CN-85 detector. The detectors were kept with the samples in closed clear plastic cups at a 2 cm distance for 60 days. The track density in the detector, and, hence, the alpha emitters from the bones were counted with an optical microscope after etching the detectors with an etchant solution (NaOH). The results showed that the optimum etching time of CN-85 when using to detect alpha emitted from natural radionuclides were 40 mins and the highest track density were found in chicken, beef, and sheep respectively.