This cross over double blind clinical trial was designed to evaluate the combination effect of five plants " Peganum harmala,Quercus infectoria, Vaccinium myrtillus, Citrullus colocynthis , Securigera securidaca" on blood sugar in adults with type 2 diabetes referred to Imam Khomeini hospital, diabetes center in Sari. The study population consist of 20 patients that will be divided into two groups randomly. One Group will receive 500 mg of prepared powder of drug ( fruit of Quercus infectoria , seed of Securigera securidaca , fruit of Vaccinium myrtillus whichever 125mg and fruit of Citrullus colocynthis and seed of Peganum harmala whichever 62.5mg )and other group will receive placebo for 8 weeks. After one week washout the drug and placebo will be replaced for next 8 weeks. Blood pressure, Fasting blood sugar (FBS), serum insulin and HbA1C will be measured at baseline of each period . After 1, 2, 4 and 8 weeks, the patients will be examined by a general physician who is blind to type of treatment. The number of remained drug will be counted and the adverse effects of drug will be recorded. Measurement of FBS will be repeated after 4 and 8 weeks and serum insulin, HbA1C after 8 weeks in each period.