Sandwich composites can be exposed to different impact loads depending on their usage areas. The behavior of the structure under impact load is an important parameter in terms of design. In this study, low speed impact test was applied to sandwich structures where 4mm, 6mm, 8mm and 10mm thick balsa woods were used in the core. 8 and 12 layers of glass fiber / epoxy composite materials with an orientation angle of [±45º]s are used on the top and bottom surfaces. The effect of outer layer number and core thickness on impact behavior has been studied experimentally. Low velocity impact tests at 15J, 30J, 45J and 60J energy values were performed on sandwich materials produced by vacuum infusion method. As a result, reaction force-displacement, energy- time and co-energy graphs are examined. It was determined that the contact force increased due to the increase in the number of outer surface layers but the absorbed energy decreased. However, it has been observed that increasing the core thickness increases the energy absorbed in the sandwich structure.