Protein biomarkers, diseased cells and pathogenic bacteria are important indications for diagnosing a disease. It is necessary to determine them at the early stage of diseases or before the outbreak of infectious diseases for a better treatment. However, determination of the protein biomarkers at trace level, diseased cells and/or pathogenic bacteria within 1000 is still a challenge. We developed an element-tagging strategy toward the protein biomarkers, and the cell membrane molecules for counting and recognizing diseased cells and pathogenic bacteria. I will talk about how to design and synthesize a chemoselective and biospecific element-tag as well as how to use isotope-dilution inductively coupled plasma mass spectrometry (ID-ICPMS) for determining the molecular biomarkers, counting the diseased cells and pathogenic bacteria. Moreover, one-dimensional targeting and two-dimensional detections strategy for seeing and counting the cells, as well as signal amplification and multiplication strategies for breaking through the bottleneck of ICPMS sensitivity will be introduced accordingly. These new analytical strategies developed allow us to quantitatively determine the molecular biomarkers, and accurately count and recognize single diseased cells and pathogenic bacterial cells for an early and precisely diagnosis of diseases.