Spectrum shaping is a good candidate for improving the efficiency of chip-to-chip communication systems. In recent years, distinct spectrum shaping schemes have been proposed for different chip-to-chip communication channels. However, a general metric on the suitability of spectrum shaping schemes is still lacking. This work addresses the problem through theoretical analysis. Two methods are utilized in the investigation, capacity achievement and error probability minimization. For the first time to our knowledge, the relation between bit error probability (BEP) and spectrum shaping is analyzed for chip-to-chip communication systems. The results facilitate the error bounds calculation of different spectrum shaping schemes, which provides a good reference for the design on the strategy of spectrum shaping.