This is a prospective, open-label, one-arm study. The study aims to assess the efficacy and safety of Etanercept therapy which help guide the clinical practice in real-world settings.

Inclusion Criteria:

1.18 to 75 years of age 2.Moderate to severe chronic psoriasis, BSA≥3% 3.Duration of psoriasis≥6 months 4.Patients must be candidate for systemic therapy or phototherapy 5.No contradiction to Etanercept 6.Informed consent must be obtained 7.For female, ß-hCG test is negative and contraception is accepted

Exclusion Criteria:

1. Diagnosis of pustular psoriasis, erythroderma psoriasis or drug-induced psoriasis
2. Having severe infections, including hepatitis, HIV and tuberculosis
3. No live vaccines 12 weeks before enrollment, through the study and 1 year after the last dose of Etanercept
4. Having significant allergies to biological agents
5. Having the previous experience of biologics
6. Having a history of malignancy
7. Having contradictions to Etanercept
8. Refusal of contraception
9. Having serious or unstable/uncontrolled illnesses

Patients with moderate to severe psoriasis (PASI>3) and bio-naive