As agricultural activity is primarily linked to rural areas, negative demographic trends characterising them present as one of the basic factors of size and age structure changes in the agricultural population. On the other hand, the modernisation of agricultural production, combined with various stimulating mechanisms, impacts its attractiveness, thus influencing the number and age structure of agricultural producers. Change in the overall agricultural activity rate reflects these two processes, making it suitable to be analysed by quantification of effects that produce these changes by applying Das Gupta’s decomposition method. The Timok Krajina region is chosen as a characteristic example due to the recent and relatively significant rise in the overall activity rate in agriculture, in contrast to the national level, where a constant decline in this rate is present. This research focuses on the difference that occurred in the last intercensal period (between 2002 and 2011), aiming to determine the impact of changes in the age structure of the active population that performs an occupation on the change of overall activity rate in agriculture in the Timok Krajina region. The research results depict that the changes in activity rate in agriculture in the examined period almost completely occurred under the influence of demographic factors, while other factors, marked as the rate effects, had a symbolic impact.