The purpose of this study is to evaluate the efficacy of Traditional Chinese Treatment(TCT) on insulin sensitivity and other related factors in type 2 diabetes by using an double-blind, randomized, parallel control and prospective study This traditional compound Chinese herb preparation is referred to this study, with three kinds of plants: 50 mg of Coptis Chinensis, 30 mg of Astragalus mambranesceus and 120 mg of Lonicera Japonica, all of which are selected by The Chinese Academy of Medical Sciences among those traditionally considered effective and safe in the treatment of diabetes.

Patients enrolled were randomized into TCT group and placebo group administrated with TCT and placebo respectively. Glucose disposal rate (GDR), fasting plasma glucose (FPG), postprandial plasma glucose (PPG), HbA1C and other metabolic components were assessed at baseline and end point

• Drug: Coptis Chinensis, Astragalus mambranesceus, Lonicera Japonica (Traditional Chinese Treatment)
• Drug: Placebo

Inclusion Criteria:

1. Newly diagnosed type 2 diabetes poorly controlled by diet only for one month
2. Obese with a BMI of 23-35 kg/m2

Exclusion Criteria:

1. Those patients used any drugs for treatment of diabetes
2. Patients with evidence of cardiac, hepatic, renal, other chronic diseases or acute diabetic complications including diabetic ketoacidosis or hyperosmolar hyperglycemic non-ketotic coma
3. Women who were pregnant or planned pregnant.