Background: There are some defects in classification of scorpions. This review is focusing on the diagnostic clue for classification and statement of defects.

Materials and Methods: Classification of scorpions has been varied during 5 years ago, repeatedly. By searching the internet, Journals' data bank and specific references, we reviewed 37 articles to design a diagnostic clue for classification.

Conclusion: This diagnostic clue can be used to classify scorpions' species.