The　heart　position　is　an　important　and　challenging　step　in　the　biological　assays　using　zebrafish　larvae　for　drug　development.　This　paper　presents　a　visual　detection　system　for　zebrafish　larval　heart　position　detection.　The　system　develops　a　video　magnification　algorithm　to　solve　this　challenging　problem　in　heart　position　detection:　the　heart　signal　of　zebrafish　larvae　in　the　microscopic　field　is　weak.　It　is　difficult,　if　not　possible,　to　be　directly　identified.　The　video　magnification　algorithm　is　used　to　amplify　the　heart　dynamic　information　of　zebrafish　larvae　so　that　the　heart　signal　can　be　directly　recognized　by　the　proposed　foreground　detection　algorithm,　and　then　the　integrated　multi-frame　image　information　is　processed　to　obtain　the　position　coordinates　of　the　zebrafish　larva　heart.　Finally,　the　proposed　algorithm　are　tested　and　validated　by　zebrafish　larval　heart　position　detection　experiments　using　the　in-house　developed　micro-robotic　system.　©　2020　IEEE.