Abstract: The pre-promoting type of vinyl ester resin was as the matrix resin and methyl ethyl ketone peroxide,dicumyl peroxide,peroxide acetyl acetone and their mixtures were chosen as the initiators. Differential scanning calorimetry( DSC) and gel experiment were conducted to evaluate curing behaviors of vinyl-ester resin with various initiator systems. The vinyl-ester/glass fiber composite laminates were manufactured by vacuum assisted resin transfer molding( VARTM). By studying the mechanical properties and cross-section appearance of composite laminates,we selected the initiator systems suitable for thick laminates manufactured at high temperatures.Resultsshowed that both by type and amount of the initiators would affect curing behaviors of the resin; proper amount of low exothermic initiator should be determined for thick-section composite laminates molding at high temperatures. After post curing at room temperature for 1 month,bending properties of the thick-section vinyl-ester/glass fiber composite laminates would be significantly improved.