Abstract: Three dimension numerical simulations were performed on laminar flow and heat transfer in a microchannel with interrupted fan-shaped reentrant cavities. In contrast to this proposed microchannel, the corresponding conventional rectangular microchannel was chosen. The numerical results indicate that the overall pressure drop effectively reduce and the ratio of friction coefficient is less than 1 because of interrupted zones. The performance of heat transfer is significantly affected by the length of interrupted zones. As the interrupted length increases,heat transfer decreases obviously. Then,according to the heat enhancement factor,(Nu/Nu₀)/(f/f₀)^{0.290 9},the No. 1 and No. 2 channel both have better overall performance than rectangular microchannel when Re > 200.