The　flow　patterns　of　immiscible　liquids　in　microscale　cross　junctions　are　experimentally　studied　and　the　influencing　factors　including　the　capillary　number　(3　x　10-　4-6　x　10-1),　flow　rate　ratio　(0.004-60),　viscosity　ratio　(0.04-2.8),　and　channel　aspect　ratio　(1/3-1)　are　systematically　analyzed.　Evolutions　of　the　interfacial　morphologies　in　different　flow　patterns　are　discussed　with　the　aid　of　force　analysis.　In　the　droplet　group,　two　different　breakup　modes　of　the　liquid　thread　are　found　with　the　symmetric　mode　for　squeezing　and　the　asymmetric　mode　for　dripping,　which　are　divided　by　a　critical　capillary　number　around　0.01.　Two　different　physical　models　for　constructing　the　scaling　law　of　the　droplet　length　are　compared　over　large　ranges　of　flow　parameters　and　the　universal　scaling　law　is　valid　to　identify　the　transitional　boundary　between　squeezing　and　dripping　regimes.　In　the　jet　group,　the　jet　width　in　different　channels　is　compared　to　the　theoretical　prediction.　A　detailed　comparison　between　the　experimental　results　in　jetting　and　the　linear　instability　theory　is　further　conducted　and　the　reason　for　the　polydispersity　of　the　droplet　size　in　widening　jetting　is　found.　Finally,　the　flow　pattern　maps　are　built　using　dimensionless　parameters　in　both　the　global　terms　and　the　local　terms.　In　contrast,　the　local　dimensionless　parameters　are　confirmed　to　show　a　better　performance　in　unifying　the　transitional　boundary　between　two　groups　of　flow　patterns.　The　obtained　results　should　be　useful　for　the　further　understanding　of　the　dynamic　mechanisms　of　the　microscale　multiphase　flow.