This study aims to determine and analyze empirically the effect of social media marketing and trust on brand affect and brand loyalty at Bank BNI Syariah Surakarta Branch. This research was conducted by taking the research location at the Surakarta Branch of BNI Syariah Bank in Karanganyar Regency. In this study, the object of this research is BNI Life Insurance customers at BNI Syariah Bank Surakarta Branch. The independent variable consists of Social media marketing and trust while the intervening variable is Brand affect and the dependent variable is brand loyalty. The results of the analysis show: Social media marketing has a positive and insignificant effect on Brand affect at Bank BNI Syariah Surakarta Branch. Trust has a positive and significant effect on Brand affect at Bank BNI Syariah Surakarta Branch. Social media marketing has a positive and significant effect on Brand loyalty at Bank BNI Syariah Surakarta Branch. Trust has a positive and significant effect on Brand loyalty at Bank BNI Syariah Surakarta Branch. Brand affect has a positive and significant effect on Brand loyalty at Bank BNI Syariah Surakarta Branch. Simultaneously the test results (F test) in the second equation are known to be the value of F = 40.282, a significance of 0.000