OBJECTIVE： To investigate the number of insoluble particle in total parenteral nutrition （TPN） solutions and to provide reference for clinical application. METHODS： 6 kinds of commonly used TPN prescriptions were selected. After prepared according to sterile operation procedure， TPN at 25 ℃ was investigated at 0， 1， 4， 8 and 24 h in terms of appearance， pH value， osmotic pressure and the numbers of insoluble particles. RESULTS： The appearance and pH value of TPN had no significant change within 24 h after preparation， and osmotic pressures were all lower than 900 mOsm/L. Study results showed that the numbers of insoluble particles quickly increased， and ≥10 μm and ≥25 μm insoluble particles exceeded the limitation of Chinese Pharmacopoeia after Lipid-soluble vitamin for injection were injected into TPN. Medium/long chain fat emulsion injection， water-soluble vitamin， electrolytes and trace elements also increased the numbers of insoluble particles.  CONCLUSIONS： Medium/long chain fat emulsion injection， lipid-soluble/water-soluble vitamin， vitamin C， electrolytes and trace elements have certain influence on the number of insoluble particle of TPN. To analyze the reason for the forming of insoluble particles has great meaning both for improving the TPN quality and reducing the harm of particles for patients.