This study concern with fatigue behavior of glass/polyester composites having surface cracks with a/t=0.7 fixed and a/c various ratios. The growth behavior of surface crack and delamination are investigated under constant-amplitude loading. Glass/polyester composites are manufactured using hand lay-up technique. Semi-elliptical surface cracks were machined on the composites materials by dentist-grinder using micro-motor. The surface crack growth and delamination crack growth are measured during fatigue cycling. Crack growth rates of test specimens were determined by using die penetration method. The surface crack growth and delamination growth are measured during fatigue cycling. Fuzzy Logic method was used to predict the delamination crack growth because the delamination crack growth is considerably difficult to measure.