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The TallObject Lightning Observatory in Guangzhou (TOLOG) can technically observe lightning flashes striking on tall buildings with different heights in the Pearl River New Area of Guangzhou. The waveform data of the lightning magnetic fields for 27 negative cloudtoground lightning (CG), which occurred on 14 high buildings obtained in 2011 and 2012, are collected and analyzed. The CGs include 112 returnstrokes (RSs), and 44% of them were single lightning processes. The softthreshold wavelet denoising method and the basic noise zero method are used for data preprocessing. The waveforms of the selected RS magnetic fields show multipeak patterns. Only the initial peak is valued in this paper due to the influence of the reflection peak existed among the high building group. The arithmetic mean of the number of strokes for a lightning is 42 The arithmetic mean of the number of strokes for 13 flash cases is 52, which occurred in the buildings below 200 m. The arithmetic mean of the number of strokes for 14 flash cases is 32, which occurred in the buildings above 200 m. The results show that the higher the building is, the more obvious the enhancement of the magnetic field peak value is. The geometric mean of the magnetic field peak values induced by the first and the subsequent returnstrokes occurred in the buildings above 200 m is respectively 22 times and 15 times of those induced by the first and the subsequent returnstrokes occurred in the buildings below 200 m. The building height had little effect on the wave head time. The wave head time of the magnetic field in the subsequent return stroke is far less than that of the first return stroke, which is consistent with the waveform characteristics of the return stroke.