A detergent box for a laundry treating apparatus comprising: a body portion providing a space for storing a detergent and having an opening at a top thereof; a housing allowing the body portion to be detachably accommodated therein; a housing through hole formed through a lower portion of the housing to allow water only from a tub of the laundry treating apparatus to be introduced therein or said water and the detergent to be discharged together; a discharge pipe protruding from a lower portion of the body portion toward the opening and having a hollow for discharging the detergent; and a discharge pipe cover configured to guide the water and the detergent into the hollow when a reference amount or a larger amount of water flows into the body portion, at least a part of the discharge pipe being inserted into the discharge pipe cover, the detergent box further comprising a block unit communicating with the discharge pipe and having a predetermined space between a lower portion of the body portion and a bottom surface of the housing to prevent water introduced into the housing from flowing into the discharge pipe, and wherein, when the body portion is accommodated in the housing, an outer circumferential surface of the body portion and a side surface of the housing are spaced apart from each other by a predetermined distance, and the side surface of the housing is arranged at a higher position than the opening such that water introduced into the housing flows into the body portion through the opening along the outer circumferential surface of the body portion, wherein the block unit comprises: a block body accommodated in the housing, at least a part of the body portion being accommodated in the block body; and a block through hole formed in a bottom surface of the block body such that the detergent discharged from the discharge pipe is discharged into the housing and preferably the block unit further comprises: a block check valve arranged outside the bottom surface of the block body to shield the block through hole. a body portion providing a space for storing a detergent and having an opening at a top thereof; a housing allowing the body portion to be detachably accommodated therein; a housing through hole formed through a lower portion of the housing to allow water only from a tub of the laundry treating apparatus to be introduced therein or said water and the detergent to be discharged together; a discharge pipe protruding from a lower portion of the body portion toward the opening and having a hollow for discharging the detergent; and a discharge pipe cover configured to guide the water and the detergent into the hollow when a reference amount or a larger amount of water flows into the body portion, at least a part of the discharge pipe being inserted into the discharge pipe cover, the detergent box further comprising a block unit communicating with the discharge pipe and having a predetermined space between a lower portion of the body portion and a bottom surface of the housing to prevent water introduced into the housing from flowing into the discharge pipe, and wherein, when the body portion is accommodated in the housing, an outer circumferential surface of the body portion and a side surface of the housing are spaced apart from each other by a predetermined distance, and the side surface of the housing is arranged at a higher position than the opening such that water introduced into the housing flows into the body portion through the opening along the outer circumferential surface of the body portion, wherein the block unit comprises: a block body accommodated in the housing, at least a part of the body portion being accommodated in the block body; and