Abstract: The release behavior of three radioactive nuclides (⁶⁰Co, ¹³⁷Cs, ⁹⁰Sr) in two types of low and intermediated level radioactive solidified waste forms were studied. The release scenario is that waste forms are totally immersed by deionized water about one year. Average effective diffusivity was used as parameter to defined release behavior. The analysis results of several samples show that the release of ¹³⁷Cs is fastest, ⁶⁰Co is slowest, and ⁹⁰Sr is middle. The total activity of radioactive nuclides in waste form has different effect on the release of different nuclides. The effect of microstructure of waste form on release of nuclides was studied based on the SEM photomicrographs.