Well-aligned zinc oxide whiskers with high density were successfully prepared on amorphous substrate by atmospheric metal-organic chemical vapor deposition. X-ray diffraction measurements indicated that the ZnO whiskers were wurtzite crystal structure, andgrew non-epitaxially on glass substrate along ZnO [0001] direction. ZnO whiskers with uniform distributions in their diameters and lengths grew vertically on the amorphous substrate. The effects of deposition conditions and the growth mechanism of ZnO whiskers by MOCVD were discussed. Both the growth habit andthe growth circumstance significantly affectedthe morphology of the whiskers.