Abstract: In this research, the compositional changes of key aroma compounds of ‘Guire No. 82’ mangoes before and after dehydration at green, semi-ripe and fully ripe stages were assessed by gas chromatography-mass spectrometry (GC-MS). The results revealed that the key aroma compounds of fresh fruit in ‘Guire No. 82’, such as β-pinene, 2-carene, β-myrcene, 3-hexene-1-alcohol, etc., possessed the highest content in the green ripening stage, which also suffer a great loss accompanying with the processing, and even not at all for decyl aldehyde. Meanwhile, the content of β-pinene and β-myrcene gradually decreased with the mango ripening, but the content of ethyl caproate and ethyl butyrate increased and reached the middle value at the half-ripe stage, and its content remained the highest after processing. Additionally, the content of ethyl hexanoate, ethyl butyrate and phenethyl alcohol reached the peak value at the full ripening stage, however, the loss of its content after processing was also very obvious, especially for ethyl hexanoate. O-cymene was only detected at the half-ripening stage, which remained after processing. The content of β-ionone was the highest in the half-ripening stage and remained at the highest level after processing. From the analysis of main aroma components, the 14 main aroma components of half-ripe mango did not disappear after processing, and the retention rate of main aroma components (original fruit flavor) reached 100%. Therefore, compared with other ripening stages, the key aroma compounds of mangoes processed into original dried fruit at the half-ripening stage of ‘Guire No. 82’ were better than those of the other two stages.