Despite the improvement of PCR technology, false-negative results from PCR detection remain as an unresolved issue, which may reduce the detection accuracy. To address this problem, an internal amplification control, which is a non-target DNA fragment, is sometime suggested at present to be included into a PCR detection system to be co-amplified with the target sequence so as to indicate the PCR inhibitors in the samples and false negative results in the detection. This is also necessary for the standardization of PCR detection system. The purpose of this article was to provide a review on the IAC-PCR in three aspects: the causes of the false-negative results appearing, the construction strategies of internal amplification controls and the applications of IAC-PCR. In addition, a brief introduction of related research work on IAC-PCR in our laboratory will be mentioned in this review, which might be helpful to develop an easy method for the construction of IAC, which could indicate the false-negative results without the decrease of detection sensitivity.