The　detection　of　metal　debris　in　oil　is　very　important　for　monitoring　the　machinery.　Based　on　the　electromagnetic　induction　principle,　a　micro　inductive　sensor　is　designed　and　fabricated.　This　sensor　is　embedded　in　oil　pipe　as　the　oil　circulates　in　the　oil　system.　The　micro-sensor　can　test　more　oil　sample　than　other　micro　inductive　sensor　with　micro　pipe.　An　analog　on-line　detection　system　is　built　and　the　detection　experiments　are　carried　out　in　this　paper.　The　oil　samples　with　copper　debris　and　iron　debris　are　detected　separately.　The　size　of　debris　is　between　88μm　and　100μm.　A　simulation　is　carried　out　to　analyze　the　trace　of　debris　in　oil　with　the　software　of　Comsol.　The　accurate　position　of　debris　in　oil　pipe　can　be　obtained　according　to　the　simulation　result.　The　position　and　the　size　of　debris　relate　to　the　inductance　signal.　With　the　accurate　position　of　debris,　the　size　of　debris　can　be　obtained　according　to　the　value　of　the　inductance　signal.　The　study　designs　an　inductive　sensor,　and　it　can　do　high-through　sample　detection.　The　simulation　gives　a　model　to　analyze　the　trace　of　metal　debris　in　oil.　The　method　has　reference　value　for　forecasting　mechanical　failure　and　monitoring　the　machinery.　The　simulation　lays　the　foundation　to　study　the　distribution　of　metal　debris.　It　is　useful　to　study　the　relation　between　the　size　of　debris　and　the　inductance　signal.　©　2014,　Journal　of　Chemical　and　Pharmaceutical　Research.　All　rights　received.