Purple jade sample was tested before and after heat treatment under oxidational atmosphere with X-ray diffractometer(XRD),ultraviolet visible (UV-VIS) absorption spectrosmeter and Raman spectrometer. XRD analysis results show that the major components of the sample are jadeite. The sample UV-VIS absorption spectra before and after heat treatment shows that after heat treatment the spikes at 437 nm and 580 nm almost disappear,while Raman spectra of purple jade brown section after heat treatment shows that the baseline presents rising trend. According to the above analysis,the following conclusion is drawn:the main color-causing ion is Fe²⁺,while Fe²⁺ changes to Fe³⁺after heat treatment and Fe₂O₃ is formed. Therefore the sample of purple jade shows brown after the heat treatment.