Abstract: Half-lives of spontaneous nuclear decay processes are calculated by a generalized liquid drop model (GLDM). The potential barrier is constructed by a GLDM, taking into account the nuclear proximity, the mass asymmetry, the accurate nuclear radius, the phenomenological shell and pairing correction. The GLDM model is to continue reproducing the experimental data for \alpha decay and cluster radioactivity, as well as to reach a reasonable calculation for the half-lives for cold fission processes. These comparisons show that the GLDM is useful tools to investigate these different decay processes in an unified theoretical framework. The influence of macroscopic energy coefficient on the potential barrier and half-lives are strongly dependent on the charge asymmetry (\eta^_Z = (Z_1-Z_2)/(Z_1+Z_2)) for the same parent nucleus during the rearrangement process. The influence of inertia coefficient on half lives also depend on the mass asymmetry \eta^_Z.