Abstract: The preparing methodology and pharmacokinetics of myocardial perfusion imaging agent 99 Tc m\|Q\-3 are studied. The optimum scheme of 99 Tc m labelling on the basis of exploring the effects of varied labelled condition on radiochemical purity is established by multivariate orthogonal experimental design. The pharmacokinetics is investigated in rabbits, and the plasma protein binding rate is also measured. “30 μL of 1 mol/L KOH in 50% ethanol, 20 μL of 2 g/L SnCl\-2·2H\-2O in degassed ethanol, 20 mg of N,N′\|ethylene\|bis (acetylacetone iminato) and 5 mg of tris (3\|methoxy\|1\|propyl) phosphine” are chosen as the optimum scheme of this labelled complex. Each of the factors exists significant effect on the radiochemical purity and there is no one\|class cross effect on the radiochemical purity between them. The pharmacokinetics of 99 Tc m\|Q\-3 conform to two\|compartment model with 0.23 ±0.09 mL/min of excelent blood clearence, an initial half\|time of 1.6±0.4 min and a late half time of 203.0±25.8 min. In vitro protein binding rate is lower.\;