Abstract: Particle analysis is of great significance in nuclear, environmental, life science, etc. Direct introduction of airborne or suspension particles into highly sensitive inductively coupled plasma mass spectrometry (ICP-MS) for on-line elemental and isotopic analysis has advantages, such as simplifying chemical treatment, avoiding contamination and obtaining fingerprint information. This paper first reviewed this technology, including principle, calibration method, sample introduction method and ion detection method. Then, some studies on the principle and calibration method conducted by our group were introduced. Two cases of its application in nuclear field were presented: determination of ultra-trace plutonium concentration in aerosol samples with complicated matrix downstream of nuclear-grade filters, and precise measurement of erbium isotopes in suspended erbium oxide particles as uranium surrogates. Finally, further development and application of this technology were proposed.