A GC-IMS system is disclosed in embodiments of the present invention. The system comprises a sample transfer device. The sample transfer device connects the gas chromatograph to the reaction region and, the sample from the gas chromatograph is transferred to the reaction region by the sample transfer device directly, instead of not through the ionization region. With the GC-IMS system, generation of sample molecular ion fragments can be avoided so that the spectrum is brevity and is easily identified; moreover, the application field of the GC-IMS system is extended to a range of analysis of organic macromolecule samples which have a high polarity, are difficult to volatilize, and are thermally instable. On the other hand, the GC-IMS system overcomes the defect of ion destruction due to neutralization reaction among positive and negative ions so as to evade the detection.