Abstract: The developments of in-situ X-ray Fluorescence (XRF) analysis techniques in the fields of Portable XRF Spectrometer, in-situ analytical methods and its applications are described in this paper. Portable XRF Spectrometer has been divided into four generations, based on the aspects of X-ray excitation sources, X-ray detectors and electrical circuit units. The paper also documents some in-situ analytical methodologies for analyzing X-ray spectra, overcoming the influence of the matrix effect, unevenness effect, moisture effect and heterogeneous effect on in-situ XRF analysis results. Finally, some applications in mineral exploration, environmental investigation, cultural relic discrimination and alloy analysis are introduced. The domestic Portable XRF Spectrometer was between generations Ⅲ and Ⅳ. The low power miniature X-ray generator and electric refrigeration semiconductor detector were dependent upon importation from foreign countries. The full digital X-ray energy spectrum collector is not yet available commercially. It is also pointed out that there are some capabilities for improving the accuracy and method detection limit of in-situ analysis. Research fields need be broadened to include the applications of Portable XRF Spectrometer.