Polymerase chain reaction (PCR) is one of the most widely used analytical tool and is an important module that would benefit from being miniaturized and integrated onto diagnostic or analytical chips. There are potentially two different approaches for the miniaturization of the PCR module: chamber-type and flow-type micro-PCR. These miniaturized PCRs have distinct characteristics and advantages. In this article, we review the necessity of micro-PCR, the materials for the chip fabrication, the surface modification, and characteristics of the two types of micro-PCR. The motivation underlying the development of micro-PCR, the advantages and disadvantages of the various materials used in fabrication and the surface modification methods will be discussed. And finally, the precise features of the two different types of micro-PCR will be compared.