Considering　the　load　mass　variations　in　real　applications,　an　adaptive　disturbance　rejection　tracking　controller　for　ball　screw　drive　system　is　proposed　in　this　article.　In　this　control　framework,　active　disturbance　rejection　controller,　proportional-integral　controller　and　feedforward　controller　based　on　the　equivalent　error　model　are　combined　to　realize　precision　tracking　control　of　the　system.　Besides,　this　control　scheme　is　designed　to　automatically　tune　the　controller　gains　according　to　the　identified　load　mass.　Comparative　simulation　and　experimental　results　indicate　that　the　proposed　adaptive　disturbance　rejection　tracking　controller　significantly　outperforms　the　cascade　P-PI　(proportional　position　controller　and　proportional-integral　speed　controller)　control　scheme　in　the　presence　of　load　mass　variations.