Diazepam is a medication of the benzodiazepine family commonly used to treat sleep disorders, insomnia and to reduce tension or anxiety. It is on the World Health Organization’s List of Essential Medicines as one of the most effective and safe medicines needed in a health system. However, some side effects of benzodiazepines such as diazepam are anterograde amnesia, confusion (especially in high doses) and sedation. Moreover, Diazepam reduces slow wave and REM sleep and also leads to sleep latency reduction. Medicinal plants have also been used for treating sleep disorders and insomnia. Myrtus communis, for instance, is recommended by Ethiopian traditional medicine and aromatherapy for reliving insomnia. It prolongs sleep duration and reduces sleep latency. This study examines the effect of diazepam and Myrtus on sleep cycle, memory correlation and long-range correlation. Experiments were carried out on 12 male Wistar rats, of weight 295-320 g, which were divided into three groups: control, diazepam, and myrtus groups. Two electrodes were implanted in the area between the neck muscle and occipital bone to record Electromyography (EMG) activity. Differential recordings from the two electrodes located in the lateral parietal and lateral occipital cortices were used to record slow wave and spindle neocortical EEG activity.This experiment has been done by Dr.Feizi in Shahid Beheshti university medical faculty. The power-frequency spectrum distribution Using the algorithm matching pursuit, Husrt exponents and singularity spectrum are compared between the groups. Results of examining sleep cycle and powerfrequency spectrum show reduction of REM sleep and high frequency bands for both diazepam and myrtus groups. In fractal analysis parameters Diazepam, however leads to fewer changes in dynamic features of sleep in comparison with myrtus.