We demonstrated a microfluidic device for high efficiency and high purity capture of circulating tumor cells(CTCs)from peripheral blood of cancer patients.The key novelty of this approach lies on the integration of a microfilter with conicalshaped holes and a micro-injector with cross-flow components for size dependent capture of tumor cells without significant retention of non-tumor cells.Under conditions of constant flow rate,tumor cells spiked into phosphate buffered saline could be recovered and then be cultured for further analyses.When tumor cells were spiked in blood of healthy donors,they could also be recovered at high efficiency and high purity.When the same device was used for clinical validation,CTCs could be detected in blood samples of cancer patients but not in that of healthy donors.Finally,the capture efficiency of tumor cells is cell-type dependent but the hole size of the filter should be more closely correlated to the nuclei size of the tumor cells.Together with the advantage of easy operation,low-cost and high potential of integration,this approach offers unprecedented opportunities for metastatic detection and cancer treatment monitoring.In this talk,we will present a comprehensive review of this approach and show that our approach is advantageous in several aspects comparing to the previous ones.