If you using dried lotus seeds: Soak lotus seeds with cool water for about 1 hour. The lotus seeds can soft. Drain and rinse well.
Clean lychees cover. Peel off and pick out seeds.
In a pot, bring water to a boil. Then add soaked lotus seeds. Bring them to a boil over medium low heat. Cook until lotus seeds are soft. Add sugar and lychees. Stir well and continue to cook for about a minute until the sugar is dissolved. Add sugar to taste.
Leave the sweet soup at room temperature for a few minutes before put it into the refrigerator.