To monitor the effect of a Metarhizium acridum strain spread in the field, a DNA molecular marker to differentiate a released strain from other strains or native isolates was developed. Sixteen arbitrary primers to amplify the genomic DNA of 51 Metarhizium strains were used and 81 polymorphic sites were obtained. Among them, 30 polymorphic bands were obtained from the strain M189. One band ascertained to be specificity to the strain M189 was sequenced and transformed as a specific SCAR (sequence characterized amplified regions) marker for this strain. The marker sensitivity was tested and confirmed by identifying strain M189 from 51examined strains. The SCAR marker was used to distinguish 3 isolates from the soil samples collected from the field and confirmed one of them being the released strain M189.