Tumor development is a comprehensive process with multiple factors involved including tumor cells,stromal cells,extracellular matrix,biochemical molecular and physics cue.Reconstructing tumor microenvironment in vitro is a critical approach for investigating tumor biological behaviors.Droplets based on microfluidic technique offer a suitable platform for tumor microenvironment with confined spatial condition.Herein,breast cancer cells,soluble bio factor and specific matrix were introduced into microdroplet and incubated for few hours.Furthermore,cell morphology.viability,and proliferation properties had been explored.Microfluidic droplet formation provides a flexible platform for manipulating cells and microenvironment with spatial-temporal control.