Semiconductor memory devices include a semiconductor substrate and a plurality of semiconductor material pillars in a spaced relationship on the semiconductor substrate. Respective surrounding gate electrodes surround ones of the pillars. A first source/drain region is in the semiconductor substrate between adjacent ones of the pillars and a second source/drain region is in an upper portion of at least one of the adjacent pillars. A buried bit line is in the first source/drain region and electrically coupled to the first source/drain region and a storage node electrode is on the upper portion of the at least one of the adjacent pillars and electrically contacting with the second source/drain region.