Objective:To design a software to do the complicated and multiple calculations automatically in routine internal radionuclide irradiation therapy to avoid mistakes and shorten patients waiting times. Methods:The software is designed on the Microsoft Windows XP operating system. Visual Basic 5.0 and Microsoft Access 2000 are used respectively as the programming language and database system here. The data and DBGrid controls and VB data window guide of Visual Basic were used to control access to and Access database.Results:Not only can the radioactivity of any radionuclide be calculated,but also the administered total iodine dose of therapy for hyperthyroidism or thyroid cancer and the total administered 153Sm-EDTMP solutions for remedy of bone metastasis of malignant tumor can be ciphered out.Conclusion:The work becomes easier,faster,more correct and interesting when the software can make the complicated and multiple calculations automatically. Patients' information,diagnosis and treatment can be recorded for further study.