In the present study, we analyzed the kinetics of the PCR-suppression effect (PS-effect) and firstly demonstrate that lower annealing temperature enhances PS-effect. Furthermore, we controlled the average size of complex PCR products over a wide range, and simultaneously amplified targets from 0.25 to 10kb by regulating the degree of suppression in a single-primer PCR. In addition, we describe an improved template-switching full-length cDNA synthesis method that greatly reduces truncated cDNA. This study provides a general guide for the design of PS-effect related PCR and is useful for representative or long-transcript enriched cDNA library construction, especially when only a small amount of total RNA is available.