Sponsor decision to terminate the study because subject enrollment was difficult.

The objective of this study is to observe and evaluate the change in renal function following conversion from cyclosporine-based immunosuppressive regimen to tacrolimus-based one.

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.