Glass samples of compositions xCuO-(30-x) ZnO-70B2O3 and xMnO2-(30-x) ZnO- 70B2O3 (where x =5 to 10 mol %) are prepared in the glass forming region. FTIR and density measurements are carried out for these glasses. IR transmission gives valuable information about the nature of bonds present in the glass matrix. It has been observed that, density of MnO2-ZnO-B2O3 glasses has greater value. This is observed that the atomic structure changes more with the incorporation of MnO2.