The synthesis and biodistribution were discribed for ^99mTc labelled fatty acid, p-[(N,N'-di-carboxymethyl) aminomethyl carboxyamino]-phenylpentadecanoic acid (CACPPA). ^99mTc-CACPPA was prepared by the reduction of Na^99mTcO₄ with stannous chloride in aqueous solution at pH 8.5〜9.5, the labelling yield and chemical purity were over 90% determined by TLC and HPLC. Biodistribution of ^99mTc-CACPPA in mice demonstrated that the highest myocardial uptake of ^99mTc-CACPPA was 18.17±2.67% ID/g. When blood disappearance of ^99mTc-CACPPA was analysed with a biexponential model, an initial half time of 1.11 min and a late half time of 20.08 min were obtained. ^99mTc-CACPPA exhibited high binding to HSA in vitro, and partition coefficients were 10.98 and 11.45 at pH7.00 and pH7.40, respectively.