This study will evaluate the efficacy and safety of calcipotriol plus betamethasone dipropionate ointment compared with calcipotriol ointment in the treatment of patients with psoriasis vulgaris for a duration of 4 weeks. The study will focus on the percentage change of the psoriasis area and severity index (PASI) from baseline to the end of week 4.

Inclusion Criteria:

• Clinical diagnosis of psoriasis vulgaris in a stable condition
• Extent of at least 10% of one or more body regions
• Amenable to topical therapy with maximum of 100 g/week of investigational product

Exclusion Criteria:

• Patients with more than 30% of body surface area involved
• Patients with facial psoriasis who need treatment
• Patients who need treatment of scalp psoriasis with WHO group IV topical corticosteroids, tretinoin or topical vitamin D derivatives
• Patients with unstable forms of psoriasis including guttate, erythrodermic, pustular, or arthritis psoriasis
• Systemic treatment of psoriasis with corticosteroids or other therapy
• Systemic antipsoriatic treatment (e.g. corticosteroids, immunosuppressive drugs, tretinoin, antibiotics, phototherapy or calcium agents) within 4 weeks prior to visit 1; or topical antipsoriatic treatment (e.g. keratolytics, topical corticosteroids, topical vitamin D derivatives, anthralin, crude coal tar, etc) within the previous 2 week period
• Patients with planned exposure to phototherapy that may affect the psoriasis during the study period