Nowadays, life science is becoming a very important part of natural science. Cell is the basic unit of organism, from which we start to crack the code of life entity. Microfluidic technology, which is being developed fast currently, is widely used in the cell research field, due to its micro-scale channels and flexible design. In this work, we focused on the determination of molecular structure and contents of the cell secretion and signaling factor. Cells were manipulated and captured on the microfluidic devices, and mass spectrometry (MS) was employed for qualitative and quantitative detection. Our key issue is connecting the microchips with MS, realizing the cell culture and drug stimulation in microchannels, and purifying the cell secretion before detected by MS. References 1) W. Zhang, N. Li, L. Lin, H. Li, J.-M.Lin, Metabolism-based capture and analysis of circulating tumor cells in an open space, Anal. Chem., 2021, 93(18), 6955-6960. 2) Q. Zhang, S. Feng, L. Lin, S. Mao, J.-M. Lin, Emerging open microfluidics for cell manipulation, Chemical Society Reviews, 2021, 50 (9), 5333-5348. 3) Q. Zhang, S. Feng, W. Li, T. Xie, W. Zhang, J.-M. Lin, In situ stable generation of reactive intermediates by open microfluidic probe for subcellular free radical attack and membrane labeling, Angew. Chem. Int. Ed., 2021, 60, 8483 –8487. 4) N. Xu, H.Lin, S. Lin, W. Zhang, S. Han, H. Nakajima, S. Mao, and J.-M. Lin, A fluidic isolation-assisted homogeneous-flow-pressure chip-solid phase extraction-mass spectrometry system for online dynamic monitoring of 25-hydroxyvitamin D3 biotransformation in cells, Anal. Chem., 2021, 93(4), 2273-2280.