Homogeneous Charge Compression Ignition (HCCI) is an advanced combustion technology being considered for internal combustion engines due to the potential for high fuel conversion efficiency and extremely low particulate matter (PM) and Nitrogen Oxides (NOx) emissions. In HCCI engines, there is no direct control method for auto ignition time. A common method to indirectly control the ignition timing in HCCI combustion engines is altering engine's parameters which can affect the combustion. Previous research has indicated that fuel chemistry has a strong impact on HCCI combustion. This work introduces a new predictive multi-zone model for the description of combustion in HCCI engines. A multi zone model with reduced fuel chemistry was developed to simulate the combustion process in HCCI engines and predict engine performance. In this work, a parametric study on Diesel/Biodiesel blends(D80B20) HCCI combustion is conducted in order to identify the effect of equivalence ratio values (0.1786, 0.27, 0.37, and 0.4762) on combustion and engine performance parameters. Two kinds of parameters will be discussed. First, in-cylinder pressure, temperature and net heat release rate diagrams at altering Diesel/Biodiesel dose (0%, 20%, 40%, 60%), then the second category, the variation of start of combustion and combustion duration which are performance parameters of HCCI Diesel Engine.