Many of the Polish sandy coasts covered by several dune ridges are in danger, threatened by high wave storms and sea level rise. Some of the sandy coasts are accumulative. Accumulated on beach sand may cause growth and development of ridge. When upper beach at the front of the first dune is densely covered by plants sand may be fixed on beach. In this way on the upper beach may be built small hillocks or shadow dunes. It is important to know how fast a new dune ridge rises. This paper shows the importance of dune field formation on the upper beach in front of the foredune for new dunes accumulation. This field has possibilities to change in an initial dune ridge. Continuous aeolian accumulation of the sand on the dune field leads to the building of a new dune ridge. This process was observed on spit of Swina Gate Barrier on west Polish coast. The accumulation was forced by pioneer vegetation, which was covering hillocks and trapping transported sand from the beach. Also speeds and wind directions (measured in Swinoujscie) may cause bigger and faster accumulation. Author observed this process during five years on area of accumulative dune coast (the Swina Gate Barrier, west Polish coast). Before the beginning of the investigations, the upper beach in front of the foredune was covered by separated hillocks fixed by pioneer vegetation. After five years these hillocks became the new foredune ridge.