An anti-human TSLP receptor antibody that specifically binds to human TSLP receptor and inhibits an action of human TSLP through human TSLP receptor. A method for preventing or treating asthma by administering the anti-human TSLP receptor antibody or an antigen-binding fragment thereof. An anti-human TSLP receptor antibody had been studied by the present inventors, and an anti-human TSLP receptor antibody including a heavy chain variable region consisting of the amino acid sequence of amino acid numbers 1 to 118 of SEQ ID NO: 1 and a light chain variable region consisting of the amino acid sequence of amino acid numbers 1 to 108 of SEQ ID NO: 3 was provided. It was revealed that the anti-human TSLP receptor antibody inhibits expression of TARC mRNA induced by TSLP and production of MDC proteins, and suppressed an allergic reaction in a monkey Ascaris antigen sensitization model.