This　paper　experimentally　investigates　pressure　drop　characteristics　of　de-ionized　water　through　a　bank　of　staggered　circular　pin-fins　with　100　μm　height　and　diameter　of　120　μm　at　lower　Re.　It　is　found　that　existing　conventional　scale　correlations　are　not　able　to　predict　the　friction　factors　accurately　at　the　micro　scale.　Especially,　the　experimental　data　are　higher　than　the　predicted　data　obtained　from　conventional　scale　correlations　for　Re　＞　140.