TTHMP (triethylenetetraaminehexamethylenephosphonic acid) was labeled with ¹⁵³Sm. The labeling condition, stability, mole ratio of ¹⁵³Sm to TTHMP, rabbit bone imaging and bio-distribution of ¹⁵³Sm-TTHMP in mice were investigated. The results showed that weak basic media and high concentration ligands were favorable to form ¹⁵³Sm-TTHMP; labeling compounds were stable at pH 7 in 7 days. The results also indicated that the chemical mole ratio of ¹⁵³Sm-TTHMP is n(¹⁵³Sm)﹕n(TTHMP) = 1﹕1 and skeleton uptake of ¹⁵³Sm-TTHMP is high((13.96±3.51)% /g at 1h post injection and (13.54±2.98)% /g at 48h post injection), while the non-target tissue uptake is relatively low, so ¹⁵³Sm-TTHMP is a promising bone tumor therapeutic agent.