Abstract: In order to determine the harm rules of Monolepta hieroglyphica (Motschulsky) in millet field, and provide scientific basis for forecasting and comprehensive treatment, the population dynamics, vertical distribution and worm rate of M. hieroglyphica were investigated in millet field in Changzhi, Shanxi in 2015 by the methods of net and observation. The results showed that Monolepta hieroglyphica began to endanger millet field at the beginning of July, and the population o Monolepta hieroglyphica increased dramatically during the late July to early August, and the population reached the maximum at the heading stage and flowering stage in the middle of August; with the finish of the flowering stage in late August, a large number of Monolepta hieroglyphica moved out of millet field. The results showed that there was a Monolepta hieroglyphica outbreak in millet field of Changzhi Shanxi in 2015, the main damaged part was icker. This study found that there was a positive correlation between worm rate and population quantity.