This research had studied the effect of Sea Nodules powder filler with different particle size (<53, <75, <106 ìm) and volume fraction of (3, 6, 9, 12) % on some mechanical properties of unsaturated polyester resin. Bending results had revealed a decrease with the increase of volume fractions, and decrease of particle size. While modulus of elasticity increased with increasing volume fraction and decreasing of particle size. Hardness and bending strength results had show an incremental increase with volume fraction increase and a decrease with particle size decreasing also the maximum shear stress was increased.