The French government has closed its miitary base in Senega.
The French embassy in Dakar said the remaining troops will run a military West African co-operation centre.
Critics have seen the presence of former colonial troops as a sign of continued French domination since independence in 1960.
France has two other major bases in Africa – one in Djibouti and one in Gabon – which will remain operational.
A spokesman for the Senegalese president said France remained an ally and strategic partner for the West African nation.
The BBC’s Tidiane Sy says there will be a ceremony on Wednesday with senior army officers present from both sides to see the lowering of the French flag.
Our reporter says it will mark a new era, but is not a complete end of French military presence.
The remaining 300 troops will launch a collective security system for African military forces and continue training commitments in the region.