Fire retardant coating (FRC) is vital in construction building as its function is to insulate heat or fire from underlying substrate. The concern of a coating also focuses on the toxicity of the material to occupants during fire hazard. Thus, in this research, water-based acrylic was used as a binder with addition of vermiculite. This paper presents the effect of vermiculite on the improvement in fire resistant of the ammonium polyphosphate-pentaerythritol- melamine (APP-PER-MEL) coating which investigated using fire protection test and scanning electron microscopy (SEM). The detail compositions of acrylic media and vermiculite were analyzed by using X-ray fluorescence (XRF). The temperature - time curve and SEM image for formulations with vermiculite show the temperature is 150°C lower than formulations without vermiculite and better char structure is observed. ©2010 IEEE.