A review of main methods of the probability theory on IF-events is presented in the case that the used connectives are Lukasiewicz , (f, g are functions, f, g : Ω → 〈0, 1〉). Representation theorem for probabilities on IF-events is given. For sequences of independent observables the central limit theorem is presented as well as basic results about conditional expectation. Finally the Lukasiewicz probability theory to the MV-algebra probability theory is embedded.