Abstract
In this paper, our objective is to analyze integrability of three famous nonlinear models, namely unstable nonlinear Schrodinger equation (UNLSE), modified UNLSE (MUNLSE) as well as (2+1)-dimensional cubic NLSE (CNLSE) by utilizing Painleve test (P-test). The non-appearance of some sort of singularities such as moveable branch points indicates a sound probability of complete integrability of the concerned NLSE. In case an NLSE passes the P-test, the studied model can be solved by implementing inverse scattering transformation (IST).