This study aimed to determine changes in the pattern of dynamics of rodent damage to lowland irrigated rice crops in the last five years (2009-2013) in An Giang,Vietnam and whether these changes are different from an earlier 5-year published data set (2003-2008) .The 5 years of data (2009-2013) ,collected every week by the Plant Protection Department of the An Giang province in the Mekong Delta,were examined and compared with the earlier 5-year published data set (2003-2008) .The study has shown that from 2009 onwards,the estimated level of damage to rice crops overall was much higher,but was second highest in the first rice crop,lowest in the second rice crop,and highest in the third rice crop.Similar patterns of fresh damage and percent loss each week were found over time between the two periods.Briefly,the area of rodent damage has increased in recent years.Increases in the rice area grown led to an increase in mean area of fresh damage by rodents.The fresh damage and percent loss each week were found to be similar over time between the two periods.This confirmed that our findings from the original analysis of earlier 5-year data set (2003-2008) are robust,and the approach used to collect weekly data by the Plant Protection Department is useful in exploring changes in rodent damage over time in relation to a changing agricultural system.