A　topological　optimization　model　of　continuum　structure　where　minimized　weight　is　taken　as　objective　and　frequency　is　referred　to　as　constraint　condition　is　developed　by　Independent　Continuous　Method　(ICM).　Continuous　topological　variables　independent　of　cross-sectional　or　shape　variables　are　used.　Frequency　constraint　is　approximately　formulated　in　terms　of　an　explicit　scheme　of　function,　based　on　Rayleigh＇s　quotient,　filter　function,　and　first-order　Taylor　expansion.　Image-filtering　method　is　developed　to　eliminate　checkerboard　patterns　and　mesh-dependence　problems.　Local　mode　and　mode　switch　are　handled　by　adding　frequency　constraint　into　optimal　model.　Numerical　examples　show　that　the　proposed　algorithm　is　robust　and　feasible.