Research on the utilization of baggase fiber as a composite material has been done, but still has shortcomings in the composite material brilliance. Therefore, the use of baggase fiber combined with coal ash can be an alternative to make a composite material. The purpose of this research is to know the effect of baggase fiber composition and fly ash composition to tensile stress and bending stress. This paper discusses the application of Analysis of Variance (ANOVA) on composite material data. There are two variables measured are variable of tensile stress and variable of bending stress. The result obtained that there is influence composition of baggase fiber and composition of fly ash at tensile stress and bending stress. Furthermore, further tests using Tukey method showed that the different composition pairs significantly were 10% -30%, 10% -40% and 20% -40% in both compositions of the two variables studied. In the determination of loss function with Signal-to-Noise (SN) Ratio with larger-is-the-better criteria, the composition of 40% baggase fiber, 10% fly ash composition and 50% matrix can produce optimal tensile and bending strength.