The present invention relates to a carbonic acid-modified nitrile-based copolymer latex, a process for producing the same, a latex composition for dip-molding comprising the latex composition and a molded article produced therefrom. More specifically, modified nitrile-based copolymer latex, which can improve the stability of latex even with the use of inorganic pigments by making the inherently modified nitrile-based copolymer latex, enables the production of a dip-molded article having a smoothness of syneresis, less stickiness, and excellent tensile strength, a process for producing the same, a latex composition for dip-molding comprising the same, and a molded article made therefrom.