To　examine　the　fluid　flow　and　heat　transfer　characteristics　in　a　microchannel　with　fan-shaped　reentrant　cavities,　the　numerical　investigations　were　conducted,　and　the　results　were　compared　with　the　conventional　rectangular　microchannel　data.　The　SIMPLEX　method　was　used　for　the　computation.　The　effects　of　volumetric　flow　rate,　heat　flux　on　the　pressure　drop　and　thermal　resistance　were　investigated　in　detail.　The　numerical　simulation　results　indicate　that　a　microchannel　with　fan-shaped　reentrant　cavities　can　improve　heat　transfer　performance　with　an　acceptable　pressure　drop　when　the　Reynolds　numbers　are　larger,　and　the　fluid　flow　and　heat　transfer　mechanism　can　be　attributed　to　the　interaction　of　the　redeveloping　of　hydraulic　and　thermal　boundary　layers,　the　effect　of　jet　and　throttling　and　the　stagnation　zone　of　laminar　flow.