A modified approach of tapered amplitude weighting for subarrayed 4D antenna arrays is proposed in this paper. Based on the combination of time weighted subarray outputs and constant element static weightings in subarrays, this approach can significantly suppress the quantitative sidelobe level of subarrayed 4D arrays. Numerical examples with three different approaches of amplitude tapers in 4D linear arrays are presented and compared to demonstrate the effectiveness of the proposed modified approach. Simulation results validate that this approach is a good trade-off of low sidelobe level and simplicity of design.