Inclusion Criteria:  Diabetic symptoms with: plasma glucose level at any time ≥11.1mmol/ L (200mg/ dL), or Fasting plasma glucose level ≥7.0mmol/ L (126mg/ dL), or plasma glucose level ≥11.1mmol/ L (200ng/ dL) for 2 h in OGTT test, or HbA1c ≥6.5%; Or those without typical symptoms should repeated the tests in another day. Han Chinese. Willingness to participate.  Exclusion Criteria:  Secondary diabetes. Participants in other clinical trials.