GaAs1‐xPxthin films have been deposited onto glass substrates at a rate of 50Å/min. in a vacuum of 5 x 10‐5Torr using a successive evaporation method. Thin films of various compositions (X = 0.3–0.9) were obtained at gallium source temperature TGa= 870°C, arsenic source temperature TAs= 275°C, phosphorus source temperature TP= 330°‐363°C and substrate temperature Tsub= 265°‐330°C. Compositional, optical (absorption) and electrical properties of the films in a thickness range of 1300–1900 Å were determined by using an X‐ray diffractometer, a grating spectrometer and an electrometer respectively. The experimental results were compared with those for simultaneous evaporation and discussed from the atomistic viewpoints.