Graphite- based microfluids were prepared via the one- step chemical method,and the effective thermalconductivity of the microfluids was measured by means of the transient hot wire method under the conditions of dif-ferent graphite contents,different ultrasonic time,different microwave time and base fluids.The results show that(1) the addition of graphite in the base fluids greatly improves the effective thermal conductivity of the microfluids;(2) the effective thermal conductivity of microfluids increases with the increase of the graphite content; (3) the ef-fective thermal conductivities of graphite- based microfluids in three base fluids (DI water,ethylene glycol and dim-ethicone) respectively increase by 102． 09%,93.17% and 225.69% at the graphite content of 1. 0%; (4) at thesame graphite content,the same ultrasonic time and microwave time,dimethicone may result in the largest effectivethermal conductivity increment while DI water may result in the smallest one; and (5) with the prolonging of ultra-sonic time and microwave time,the increment of effective thermal conductivity of graphite- based microfluids signifi-cantly reduces.