This research aims to develop the cement board from coconut shell ash. The Portland cement type1: fine sand: tap water ratio is equal to 1: 0.4: 0.33 by weight. The 5 ratios of Portland cement type1: coconut shell ash include 1: 0.12 1: 0.13 1: 0.14 1: 0.15 and 1: 0.16 by weight. The cement board production uses the pressure casting in normal temperature (30 – 35 degree of Celsius) and controls the 0.75 g/cm3 of density then test the properties of cement-bonded fiberboard follow TIS 878-2537 standard (cement bonded particle board: high density). From the results 1: 0.12 is the most suitable ratio of cement board from coconut shell ash. This developed cement boards can reduce the quantity of coconut shell ash waste and have the good thermal insulation.