Purpose: To assess characteristics the application of mobile medication system and medication administration error (MAE) alerts in a general hospital. Methods: The subject hospital adopted a mobile medication system in 2016. All medication administrations in the general wards and ICUs were automatically recorded in real-time using identification barcodes, drug barcodes, and hand-held point-of-care devices. MAE alert logs were recorded from April 1st 2017 to March 31st 2018. For this study analysis was done using Pearson’s chi-squared test for potentially related factors of MAE alerts included administration time, order type, medication route, and length of nurse’s employment. Results: The total number of medications during the period of this study was 3,227,990. Among them, 2,698,317 medication doses were recorded, resulting in the system application rate of 83.6%. The system application rate was significantly correlated with all factors related to potential MAE alters. In this study 23,314 MAE alerts(0.9% of the total medication doses) were identified. The MAE alerts were related to new (OR=2.26, p<.001) and emergency (OR=2.25, p<.001) orders, and administration at a non-standard time (OR=2.032, p<.001). Medication route (p<.001), and nurse’s employment duration(p<.001) were also related. Conclusion A mobile medication system contributes to improving patient safety by preventing potential MAEs. The MAE alerts were related to administration time, order type, medication route, and duration of nurse’s employment. In order to prevent medication administration errors, it is necessary to standardize the process of medication and create an environment in which medication administration can be performed in a planned situation.