The Present invention relates to a sweet potato porridge and a preparing method thereof, and more particularly, to a sweet potato porridge of which the salinity is adjusted by kelp containing a lot of "alginate", which promotes a bowel movement, to increase a constipation preventing effect, and a preparing method thereof. The sweet potato porridge of the present invention comprises, based on the total 100 wt%, 3.8 wt% of sweet potato, 4.8 wt% of seaweed, 3.5 wt% of kelp, and 12.4 wt% of pineapple.
