The purpose of the study is to examine the safety and effectiveness of sirolimus treatment for people with systemic sclerosis.

The investigators perform a multi-centre, double-blind pilot trial with sirolimus in SSc.The investigators evaluate the effectiveness and safeness of sirolimus for Systemic Sclerosis by randomized controlled study (sirolimus 2mg/d (N = 36) versus placebo group (N = 36)).

Each SSc patients (n=72) received sirolimus or placebo (active group: placebo group =1:1, 2mg/day， oral administration, (SIR 2mg, po., Qd) .

The end points were the changement of modified RSS and the adverse events or severe adverse events onset.

Inclusion Criteria:

• Meet the American College of Rheumatology criteria for the diagnosis of SSc, 2013.
• Disease duration less than 5 years.
• mRSS was under stable level (>1 month) at the time inclusion.
• Negative urine pregnancy test
• Written informed consent form

Exclusion Criteria:

• Diagnosed with localized scleroderma .
• Added with immunosuppressor in one month such as MTX, AZA, CYC.
• Added with anti-fibosis drug in one month.
• Prednisone >10mg QD before inclusion.
• Sever chronic liver, kidney, lung or heart dysfunction; (heart failure (≥ grade III NYHA), hepatic insufficiency (transaminases> 3N) )
• Serious infection such as bacteremia, sepsis
• Mental disorder or any other chronic illness or drug-abuse that could interfere with the ability to comply with the protocol or to give information
• Cancer or history of cancer cured for less than five years (except in situ carcinoma of the cervix or Basocellular carcinoma)
• Positive HIV test
• Positive urine pregnancy test
• Combined with the other connective tissue diseases