Let Xn be the finite set {1, 2, . . . , n}, and POn = On ∪ {α : dom(α) ⊂ Xn(∀x, y ∈ Xn), x ≤ y =⇒ xα ≤ yα} be the semigroup of all partial order-preserving transformations from Xn to itself, where On = {α ∈ Tn : (∀x, y ∈ Xn)x ≤ y =⇒ xα ≤ yα} is the full order preserving transformation on Xn and Tn the semigroup of full transformations from Xn to itself. A transformation α in POn is called quasi-idempotent if α \neq α 2 = α 4 . In this article, we study quasi-idempotent ele ments in the semigroup of partial order-preserving transforma tions and show that semigroup POn is quasi-idempotent gener ated. Furthermore, an upper bound for quasi-idempotent rank of POn is obtained to be d 5n 2 −4 e . Where d xe denotes the least positive integer m such that x ≤ m ≤x+1.