The synthesis of ultrafine ZnS nanobelts by controlling evaporation and agglomeration rates was investigated. The range of belt width was 5-30 nm, and peaked at 10-20 nm. The belt thickness varied with width and was typically of only several nanometers. High-resolution transmission electron microscopy was used to characterize the beltlike product. By measuring over 100 nanobelts, it was confirmed that the typical width of the belts is in the range of 5-30 nm and peaked at 10-20 nm. FE measurements show that the ultrafine ZnS nanobelts are decent field emitters. It was observed that the length of ultrafine ZnS nanobelts is up to several or tens of micrometers, whereas their thickness is likely to be only several nanometers.