Plant architecture-related traits are important in breeding maize (Zea mays L.). Suwan maize germplasm has been widely used in tropical/subtropical regions because of its abundant genetic diversity compared to temperate germplasm. To investigate the influence of the genetic base on the detection of quantitative trait loci (QTLs) controlling plant architecture-related traits, a population of 150 F2:3 progeny derived from ZHL908 and HCL645 were developed and genotyped using the genotyping by sequencing (GBS) method. Through inclusive composite interval mapping using 5636 SNP markers, a total of 25 QTL-controlling plant architecture-related traits were identified. Seventeen QTLs had been previously reported, which may be important in future MAS breeding. Eight new QTLs were reported for the first time in this study. Of the 25 QTLs, 7 QTLs were related to plant height (PH), 4 QTLs were related to ear height (EH), 4 QTLs were related to leaf number (LN), 5 QTLs were related to tassel length (TL), and 5 QTLs were related to tassel primary branch number (TPBN). Four plant architectural trait-related genes, sparse inflorescence1, ramosa3, dwarf1, and zea floricaula/leafy1, were found to be located in qLN4, qTL5, qTPBN1 and qTPBN5, respectively. These results not only provide new insights into the genetic research investigating maize plant architecture variation but also provide molecular evidence that may enable the improvement of Suwan germplasm in modern maize breeding. [ABSTRACT FROM AUTHOR]