Micro　stereovision　system　with　stereo　light　microscope　(SLM)　has　been　applied　in　micromanipulation　systems.　There　is　coupling　connection　between　two　optical　paths　of　stereo　light　microscope.　Coupling　intension　corresponds　with　two　factors,　the　first　is　structure　of　SLM,　and　the　second　is.　position　of　object　point　in　the　field　of　view　of　SLM.　A　correlation　function　is　proposed　to　describe　coupling　intension　of　two　optical　paths　for　quantity　of　correlation　between　couple　optical　paths　of　SLM　in　this　paper.　Quantified　results　are　applied　to　error　analysis　of　an　imaging　model.　Experiments　show　that　correlation　of　optical　paths　of　CMO-SLM　is　little　more　than　that　of　G-SLM,　and　error　must　be　considered　when　a　pinhole　imaging　model　is　used　to　analyze　its　correlation.