Crystalline structure and magnetic properties of ordered and disordered Fe1-x-yMnxPty films (100 nm thick) were studied, and the magnetic phase diagrams were investigated. In ranges of both 0 ≤ x ≤ 0.4 and 0.45 ≤ y ≤ 0.85, all of the films had A1 type (face-centered cubic) disordered structure before annealing. At room temperature, the saturation magnetization (Ms) of the disordered Fe0.5-xMnxPt0.5 and (Fe0.5Pt0.5)1-xMnx films decreased with increasing the amount of Mn addition (x) due to its decreasing of the Curie temperature (Tc). After annealing at 600°C for 1 hour, almost of all films with ranges of 0 ≤ x ≤ 0.4 and 0.45 ≤ y ≤ 0.85 had L10 type (face-centered tetragonal ; a = b > c ) ordered structure. Ordered (Fe0.5Pt0.5)1-xMnx films with 0 ≤ x < 0.29 excepting x = 0.23 had high Ms of 500 ≤ Ms ≤ 800 emu/cm3 . These results suggest realizing an advantaged bit patterning process using the order-disorder transition.