Genomic DNA were prepared from 5 sibling species of Anopheles hyrcanus group including An. sinensis (ASS), An. anthropophagus (ALA), An. liangshanensis (ALS), An. crawfordi (ACW) and An. xiaokuanus (AXK). High molecular weight DNA from each species were cut with three restriction endonucleases (Bgl II, Hae III and Pst I) and the DNA fragments analysed by agarose gel electrophoresis and ethidium bromide staining. Three enzymes (Bgl II, Hae III and Pst I) produced unique fragments in all sibling species tested. A diagnostic restriction fragment length of DNA from 5 sibling species of An. hyrcanus group may be derived from a single restriction enzyme pattern (i.e. Bgl II). The results demonstrated that the restriction fragment length differences of repetitive DNA could used as a tool to distinguish sibling species of An. hyrcanus group.