HEDTMP (N-(2-hydroxyethyl) ethlenediamine-1,1,2-tri(methylene phosphonic acid)) was labeled with ¹⁵³Sm. The formation condition, stability, rabbit bone imaging and mouse bio-distribution of ¹⁵³Sm -HEDTMP were investigated. The results showed that weak basic media and high ligand's concentration were favorable to form ¹⁵³Sm-HEDTMP, and neutral or weak basic media increase the stability of ¹⁵³Sm-HEDTMP. And the higher the concentration of HEDTMP was, the more stable the labeling complex was. Bio-distribution study indicated the uptake of ¹⁵³Sm-HEDTMP in skeleton was high ((25.68±1.22)ID%/g bone at 3 h post injection and (16.56±1.01)ID%/g bone at 48 h post injection), while the non-target tissue uptake and retention were relatively low, so ¹⁵³Sm-HEDTMP is a promising bone tumor therapeutic agent.