A drug carrier characterized by mainly containing a polyethylene-glycol-modified phospholipid and a cationic lipid and containing the polyethylene-glycol-modified phospholipid in a concentration within a specific range. The drug carrier, which is of the in-blood residence type, is characterized by comprising a polyethylene-glycol-modified phospholipid represented by the following general formula (I) or a pharmaceutically acceptable salt thereof: [wherein X represents the following (II) or (III) and n is an integer of 30-150] [wherein R 1 represents a saturated linear C 17-22 fatty acid residue] and 2-O-(2-diethylaminoethyl)carbamoyl-1,3-0-dioleoylglylcerol. It is further characterized in that the polyethylene-glycol-modified phospholipid represented by the general formula (I) is contained in an amount of 30-50 wt.% based on the total amount of the lipids in the drug carrier.
