The mapping relationships among the motion coordinate errors along nine single coordinate lines,the straightness error and 21 other initial error items,and the mapping relationships among the tool geometric errors related to work-piece space and initial error items are researched using laser interferometer for a three-axis machining center.Then,a nine-line measurement method and a volumetric error compensation method are put forward. Moreover,the rapid identification of initial error items and compensation of volumetric error are realized.