Nowadays, the use of composite has been commonly used in human life, like on household equipment, furniture biomedical and automotive. Composite material consists of matrix and filler. Polypropylene has been used as matrix because of its elasticity, lightness, and cheapness. Calcium carbonate is a kind of the composite fillers which is commonly used because it is abundant and cheap. In the automotive industry, it usually used composite as car interior such as a dashboard. In the process of making dashboard itself, it needs to conduct a lot of research about plastic composite to get the type of material that is suitable to use in making car dashboard. This research is to investigate the influence of CaCO3 size particle to tensile, bending and hardness characteristics of CaCO3/PP composite. This research was performed by creating multipurpose specimen based on ISO 294-1:2012 standard with polypropylene composite material with the addition of 15% CaCO3 filler with microparticle variations of as-received (132μm), 200 mesh (74μm), 400 mesh (37μm) with injection molding manufacturing machine. The performed tests are tensile, bending and hardness tests in accordance to ISO 527-1 standard, ISO 178 standard and ASTM 2240, respectively. Composite fractures were analyzed using optical and scanning electron microscopy (SEM) to determine the composite microstructure. The research produced the following results. The tensile strengths of PP/CaCO3 are 31.08 MPa, 30.48 MPa and 29.86 MPa for as-received, 200 mesh, and 400 mesh, respectively. The bending test result values for PP/CaCO3 are as-received 47.52 MPa, 200 mesh 43.3 MPa, and 400 mesh 48.08 MPa. The hardness test result values for PP/CaCO3 are as-received 68.62 Shore D, 200 mesh 68.94 Shore D, and 400 mesh 69.7 Shore D. SEM micrographs showed the smaller mesh size of the CaCO3 particle size the more evenly distributed. The results concluded that the addition of CaCO3 fillers makes the composite material stiff and hard.