Ranolazine (RZ) is an antiischemic/antianginal agent employed in therapy of cardiovascular diseases such as myocardial infarction, variant and exercise-induced angina and arrhythmias constipation, headache, nausea and dizziness are the most common side effects. So the aim of the present research work was to formulation development and characterization of modified release RZ loaded EC microspheres by o/w emulsion solvent diffusion evaporation technique with different ratio of drug and ethyl cellulose as a polymer in order to achieve high entrapment efficiency and prolonged release characteristics. The prepared microspheres were characterized by Scanning electron microscopy (SEM), percent yield, micrometrics properties, Fourier transformer infra red spectroscopy (FTIR), percent entrapment efficiency and percent drug release characteristics. The size of microspheres formulations (F1 to F6) were in range of 20±1.2 to 54±1.7μm, percent yield 78.21±2.31 to 94.24±1.21%, percent drug entrapment efficiency 53.25±0.65 to 85.76±0.78% and percent drug release 56.87 ± 0.34 to 92.74 ± 0.83 % up to 12 hrs. IR study showed no interaction between drug and polymer; no degradation during microspheres preparation and stable at storage conditions. All microsphere formulations showed various drug releases kinetic but F2 formulation followed first order drug release kinetics and 92.74 ± 0.83% drug release for prong period of time. From the study, it was investigated that free flowing spherical microspheres of RZ could be prepared successfully by solvent diffusion evaporation technique with high entrapment efficiency and prolong release profile characteristics.