The pentaquark state of Θ+(uudds) has been observed to decay with two decay modes: Θ+ → nK+ and Θ+ → pK0. The decay probability ratio of the two decay modes is studied with general symmetry consideration of isospin, spin, and parity. We arrive at a result of the ratio Γ(Θ →nK) Γ(Θ+→pK0) = (α−β) 2 (α+β)2 (1 k2 )2L+1, which is valid for the Θ+ state to be a pure isoscalar or isovector state, or a...