The present invention relates to the detection of a target nucleic acid sequence in a real-time manner using a target signal generating primer (TSG primer) having dual interactive labels. The present invention allows for both target amplification and signal amplification by introducing dual interactive labels into a primer used in PCR reactions, ensuring real-time target detection by PCR reactions without the use of complicated oligonucleotides. The present invention could be free from the troublesome matters and shortcomings associated with conventional real-time PCR methods. The present invention allows for successful real-time target detection by using only a labeled primer. Also, the present invention can obtain strong signals indicative of the presence of target nucleic acid sequences in both a liquid phase and solid phase.