Methyldiphenylphosphine oxide (MDPPO) was characterized by infrared spectroscopy (IR), nuclear magnetic resonance ((1)H NMR and (31)P NMR), and a differential scanning calorimeter (DSC). Using a static analytical method, the Solubilities of MDPPO were measured in benzene, toluene, ethylbenzene, o-xylerie, m-xylelle, p-xylene, ethyl acetate, and binary solvent mixtures: acetone + n-hexane (Volume ratio = 3:7) and benzene + ethyl acetate (Volume ratio = 1: 1). The experimental results were correlated With an empirical equation. The estimated uncertainty of all the Solubility values was within 2.0 %.