Single-cell sequencing elucidates unique insights in understanding intratumor heterogeneity and clonal evolution. Both chromosomal structural change/copy number alteration/variation (CNA/CNV) and driver gene mutation events appear somatically at the early stages of oncogenesis and are critical in cancer initiation, tumor progression, and therapy response. We have developed a high-throughput single-cell DNA analysis platform that leverages droplet microfluidics and a multiplex-PCR-based targeted DNA sequencing approach. The platform demonstrates high-sensitivity detection of SNVs and indels in the same cells and generation of high-resolution maps of clonal architecture based on mutational profiling.