Abstract: Fluorescent-based real-time PCR is widely used for quantification of nucleic acids. It is becoming one of the most important techniques for molecular biology and biotechnology.Real-time PCR assay is easy to perform, capable of high throughput, and can combine high sensitivity with reliable specificity. The technique is evolving rapidly with the knowledge of new enzymes, chemistry and instrumentation. The principle of real-time PCR and its application in quantifying plant nucleic acids is reviewed.