Track etch rate characteristics of CR-39 plastic detector exposed to28Si ions of 670 MeV energy have been investigated. Experimental results were obtained in terms of frequency distribution of the track diameter, track density and bulk etching rate. A dependence of the mean track diameter on energy was found. The application of the radiation effect of heavy ions on CR-39 in the field of radiation detection and dosimetry are discussed. Results indicated that it is possible to produce etchable tracks of28Si in this energy range in CR-39. We also report the etching characteristics of these tracks in the CR-39 detector.