Heat　transfer　characteristics　associated　with　the　forced　flow　of　de-ionized　water　over　diamond　shaped　micro　pin-fin　bundles　have　been　experimentally　investigated.　It　is　shown　that　the　forced　convection　over　micro　pin　fin　heat　sinks　is　a　very　effective　heat　transfer　mode.　The　dependence　of　the　Nusselt　number　on　the　Reynolds　number　is　considerably　notable.　The　total　thermal　resistance　decreases　with　the　increasing　pumping　power.　Compared　with　the　convection　thermal　resistance,　thermal　resistance　due　to　the　increase　in　liquid　temperature　has　more　significant　effect　on　the　performance　of　the　micro　heat　sink.