This work presents a near-field microwave resonator combining with a micro-channel and cell trappings for detecting biological cells. A hairpin sensor with a high-Q dielectric resonator allows the detection of a small variation of DUT in the micro-channel by measuring the scattering parameters responses at resonance frequencies of around 2.2 GHz. The sensor is a microfluidic device constructed from polydimethylsiloxane (PDMS) and negative photoresist (SU-8) using micro-electro-mechanical-system (MEMS) technology to measure the characterization of biological cells under liquid medium. Measurements and analysis of Dulbecco's modified Eagle's medium (DMEM) and B16F10 melanoma cells (mus musculus skin melanoma) were then performed. These analysis results are helpful for further portable biomedical applications such as cell trapping, measurement, and characteristics.