Hydrogel are polymer materials with covalent or non-covalent crosslinks containing large fraction of water.Hydrogel microfluidics applies hydrogel for fluidic control in microfluidic devices.The unique properties of hydrogel including stimuliresponsiveness and biocompatibility endow additional layer of fluidic control for microfluidics.In this talk,recent research progress of our research group on hydrogel microfluidics will be reported.First,agarose droplet microfluidics for single-molecule amplification will be presented.The thermo-responsive property of agarose was used for highly efficient generation of uniform,size tunable agarose-in-oil droplets for single molecule amplification and flexible storage,transport,manipulation of amplified DNA product in agarose beads,enabling highly throughput molecule screening for functional nucleic acids,large-scale single cell gene expression study,and rare pathogenic cell detection.Second,the biocompatibility of hydrogel was used to construct microcollagen gel array for high throughput long-term single-cell culture and single-cell analysis under 3D culture conditions.Finally,target-responsive hydrogel was developed and used for portable visual quantitative point-of-care testing.These examples illustrate that hydrogel are useful materials for microfluidics.