We report on the growth and structural, electrical and magnetotransport characteristics of epitaxial manganese perovskite (Pr1-xSrx)(y)MnO3-delta (PSMO) thin films by oxygen plasma assisted molecular beam epitaxy (MBE). Special attention was given to the non-stoichiometric phase, which exhibits interesting properties such as different phase transition temperatures and marked low field magnetoresistance. Under appropriate growth conditions, 2D step-flow growth mode has been realized with super smooth film surfaces. The structure characterization and magnetoresistance properties were studied and analyzed. (C) 2002 Elsevier Science B.V. All rights reserved.