The lattice constants,total energies and densities of states of transition metals Fe．Ru and Os in ⅧB group with different crystalline structures have been calculated,and the results have been compared with the results of projector augmented wave(PAW)method in first principles，CALPHAD and experiments．It is found that the lattice stability results in this paper is △Gbcc-hcp〉△Gfcc-hcp〉O，agreeing well with thoSe ofPAW method in first principles and CALPHAD method in spite of bcc-Fe．And further analyses of lattice stability from electronic structures show that crystalline Ru and Os with hop structures have the obvious character of stable phase，agreeing with the results of total energy calculations．It is found from the analyses of atomic populations that the transiton rate of electrons from S state to P for hcp，fcc and bcc crystaIls increase with the increase of elemental pe~od to form stronger cohesion，higher cohesive energy or stabler lattice between atoms in heveavy metals．