In this paper, a new quasi-atomic model of metal, new concepts of effective valence electron number and equaivalent orbital radius of atom are put forward. Problems related to metal are studied and analysed by using the model and the concepts. Characteristic parameters concerned with metal can be effectively calculated with under standing the electron distribution of metallic atom, namely the principal quantum number and total number of valence electron of atom. Parameters which can be calculated are effective nuclear charge number of atom, density of free electron, atomic radius, Fermi energy and work function of the metal concerned. Atomic radius and work function of 68 metals and density of free electron of 17 metals are calculated and compared with experimental values, results show that the former two are both quite in accordance with the experimental results and the latter one is better than the results calculated by free-electron model. Thus it can be seen that the model and methods are in conformity with the actual situation of metals, and its applications are proved to be reliable.