A Study to Assess the Safety and Efficacy of a Tacrolimus Based Immunosuppressive Regimen in Stable Kidney Transplant Recipients Converted From Cyclosporine Based Immunosuppressive Regimen

Inclusion Criteria: * Patients received a kidney transplant at least 12 months before enrollment. * Patients whose dosage of previous immunosuppressants has not been changed and remained for at least 4 weeks before enrollment, and blood trough level of cyclosporine is 100 to 200 ng/mL. * Patients who have the side effects (hypertension, hyperlipidemia, gingival hyperplasia and hypertrichosis/hirsutism) during use of cyclosporine. * Serum creatinine \< 2.3 mg/dl at enrollment * Female patients of childbearing potential must have a negative serum pregnancy test prior to enrollment, and agreed to use effective contraception during the trial. * Patients considered clinically stable Exclusion Criteria: * Patients who have previously received an organ transplant other than a kidney. * Patients who have had acute transplant rejection within 12 weeks, or acute transplant rejection requiring antilymphocyte therapy within 24 weeks prior to enrollment. * Patients newly diagnosed malignant tumors after organ transplant, but the patients treated completely with basal or squamous cell carcinoma of the skin are excepted. * Patients who have an underlying disease such as focal segmental glomerulosclerosis (FSGS) or type II membranoproliferative glomerulonephritis (Type II MPGN). * Proteinuria \> 2 g/24 hrs. * Patients who have "Creeping creatinine" (a 20% increase in their creatinine for six months before their enrollment). * Patients whose Alanine Aminotransferase (ALT) and/or Aspartate Aminotransferase (AST) is twice higher than the normal range in the center. * Patients who have liver cirrhosis. * Patients who are pregnant or breastfeeding. * Patients who had been HIV-positive. * Patients who have a known allergy to Prograf® or its ingredients, steroids or adjuvants. * Patients who have an unstable medical condition that may affect the evaluation of the study's objectives. * Patients who are receiving prohibited concomitant medications or who received those medications within 28 days of their enrollment. * Patients who are currently participating in another clinical trial or who received the investigational drug in another trial within 28 days of their enrollment. * Patients who are at the risk of drug abuse or mental disorders or communicate difficulties.