Abstract: In order to develop new phosphine schiff base mixed complexes of 99 Tc m used for myocardial imaging, an N 3S ligand(MVNE) and four phosphine ligands are synthesized. 99 Tc m MVNE,which is prepared under room temparature through ligand exchange reaction,reacts with the four phosphine ligands respectively to obtain mixed complexe of 99 Tc m MVNE phosphine. Biodistribution of the four complexes in mice indicates that uptake is demostrated in heart,the activity is cleared rapidly from blood and the clearance half time is less than 10 min.However,the retention ability of the four complexes in heart is not ideal and heart/background ratios is low. The distribution results in mice indicate these complexes exhibit certain myocardial uptake.