Organic matter amendment is key control tool for enhancing the soil aggregation and other soil chemical, physical and biological properties. This study was therefore carried out in an organic vegetable field in the experimental field of the Agricultural Research and Application Centre of Suleyman Demirel University in 2010-2013. The effects of control (Ct), farmyards manure (FYM) and green manure (GM) (common vetch, Vicia sativa L.) on the percentage of soil aggregation. The percentage of aggregation was calculated by the determination of total and dispersed clay+silt in the four aggregate-size groups (8.0-4.0, 4.0-2.0, 2.0-1.0, <1.0 mm) which were obtained by dry-sieve method. Results showed that, organic matter appli-cations increased the percentage of aggregation. Year, treatment, depth and aggregate sizes lead to differences (P<0.001) in the percentage of aggregation. The maximum aggregation (90.67%) with the size of 8.0-4.0 mm was determined in 0-10 cm depth by FYM application in 2013 experimental year; whereas the minimum aggregation (79.08%) was observed for Ct treatment in 0-10 cm depth in 2012. It can be concluded that farmyard manure was found to be more effective than the green manure in improving soil aggregation.