The method of lifetime measurement has been used to investigate the nucleation of the vapor phase in a superheated liquid nitrogen-helium solution. Temperature dependences of the mean lifetime of a metastable solution have been obtained in experiments at pressures p = 0.5, 1.0 MPa and several values of the mixture concentration. The nucleation rate J has been calculated. It varied in experiments from 104 to 10(8) s (1) m (3). The results of experiments are compared with homogeneous nucleation theory. The paper deals with the size effect on the surface tension of a nucleus and the work of its formation. (c) 2008 Elsevier B. V. All rights reserved.