The liquid crystalline (LC) ordering of nematic mesophase was investigated by measuring the transmitted depolarization light intensity of samples varied with the temperature.The depolarization intensity of a light beam passing through the sample between crossed polarisers increased with temperature during heating,and then it was decreased when the temperature clossed to Ti. The increasing of the depolarization intensity means the growth of LC ordering or domains.This result indicates that the LC ordering in different within temperature range of nematic mesophase.So that the crystallization behavior of samples crystallized from the mesophase melt of different temperatures will be different.The isothermal crystallization from mesophase melt of different LC ordering was determined by DSC.The samples were first melted at different temperature corresponding to different LC ordering for 30 min,and then crystallization was carried out at same temperature to compare their rates.The results obtained indicate that the crystallization rates from mesophase melt of different temperature were quite different for this thermotrpic aromatic polyester.It can be seen from compareison of the data between the depolization light intensity and the crystallization rate that the crystallization rate increases with increasing LC ordering or domain size at first,and then as the LC ordering was decreased the crystallization rate becomes slower when the temperature of mesophase melt close to Ti.These observations could be interpreted that high LC ordering,or large domain size,made it easy to crystallize.