Abstract: With a method different from some reference's(3〕,without any assumption abo-ut the arm structures the inertia data of robot PUMA 560 have been computed bymeans of practical measurement and reference to some mechanical drawings withoutmarked size and 258 dynamic parameters of six joints are correctly derived in symbolicform.Thereby a full set of dynamic equations has been obtained.It provides a satisfa-ctory model for dynamic control purpose.The dynamic equations of the first threejoints have been used in the paper(1〕with very encouraging results.