The present invention relates to a benzylphenyl glucopyranoside derivative having an excellent inhibitory effect on human SGLT1 and/or SGLT2 activity. There is provided a compound or a pharmacologically acceptable salt thereof represented by the following general formula (I): wherein R1 represents a hydrogen atom, an amino group, a hydroxy C1-C6 alkyl group, etc.; R2 represents a hydrogen atom, etc.; R3 represents a C1-C6 alkyl group, a hydroxy C1-C6 alkyl group, etc.; R4 represents a hydrogen atom, a C2-C7 acyl group, etc.; R5, R6, R7, and R8 are the same or different and each represents a hydrogen atom or a C1-C6 alkyl group, provided that R5, R6, R7 and R8 are not hydrogen atoms at the same time; n is 0 to 4; and X is CH or N.