To achieve single cell mass spectrometry,our group has worked on fundamental theory for ion suppression,development of novel ambient ionization mass spectrometry and the application for living cell analysis.The major contribution was to firstly overcome both matrix effect and ion suppression effect during conventional electrosrpay process,the advantages of ambient ionization methods were introduced to the more common used technique.With induced high voltages,inductive electrospray was developed,to meet the requirements of high sensitivity,high selectivity and high throughput for mass spectrometry.Finally,in cell mass spectrometry has enabled direct metabolite/protein measurements in single living cells.Now we are working on the possibility to accomplish proteomics at single living cells,which might preserve informations of protein/protein or protein/ligand interactions with their real status in living cells.