Abstract: Zhundongcoalcannot bedirectlyused due to its high sodium content. A 0. 25 t / d test systemof high alkali coal thermochemical conversion was applied to investigate the alkali metal transformation of high-sodium Zhundong coal during gasificationat different temperatures. The transformation of sodium was investigated with inductive coupled plas- ma equipped with atomic emission spectrometer (ICP-AES),X-ray diffraction (XRD) and scanning electron micros- copy with an energy dispersive X-ray spectrometer(SEM-EDX). Meanwhile,the transformation of sodium during gasifi- cation was simulated by FactSage6. 1. The results show that Na in bottom ash decreases while Na in fly ash increases as the gasification temperature increases. Na in the bottom ash exists mainly as sodium aluminum silicate while Na in the fly ash exists mainly as sodium chloride. No slag is found in the bottom ashand fly ash,and no defluidization occurs during gasification. Corrosionis found due to the high Cl content.