Coconut shells and fibers are valuable aggregates as potential alternative for commercialization in concrete production. Fibers control cracking due to shrinkage while shells are hard stony endocarp but lightweight. Tests of sieve analysis, specific gravity, moisture content, mechanical property and the comprehensive test in accordance with the ASTM (Standard Test Method for Sieve Analysis of Coarse Aggregate, 2011) were employed to the hollow block-coco shell /fiber (HBsf).With the same curing age of 28days, HBsf is much darker than the (CHB) concrete hollow block. Both textures are rough and have the same dimension of 100mm x 400mm x 800mm. HBsf has a density of 1213.59 kg/m3 while CHB has a density of 1529 kg/m3. CHB reached a load of 11.65 KN to 17.58 KN and stress capacity of 0.57 MPa to 0.8 MPa while HBsf has reached a load of 34.42 KN to 43.5 KN and a stress of 1.82 MPa to 2.11 MPa .It implies that the thermal conductivity of HBsf for cold and warm temperature resist freezing and heating. The average modulus of elasticity of CHB is 525 MPa, while HBsf is 1400 MPa. HBsf has greater modulus of elasticity than CHB. It is a good indicator as fire resistant thus sturdy to crushing, absorption and surface moisture. It suggests fabricating shredder to mechanically separate the strands into individual fibers and grinder for coconut shells to have uniform sizes of particles (pea size). The mass production of HBsf is recommended to test the mechanical properties.