Lab-on-a-chip (LOC) systems have been widely used in chemical and medical analyses. In this study, a novel T-shaped electroosmotic micromixer was simulated and the effects of different parameters on the mixing process were examined. These parameters include; inlet angle, number of conducting hurdles, arrangements of the hurdles, geometry of hurdles and chambers, aspect ratios of the channel cross-sectional profile, hurdle radius, and depth. It was found that the inlet angle has a direct influence on mixing index (sigma). The effect of various number of hurdles (one, two, three and four hurdles) and their orientations was investigated. Simulations revealed that using two conducting hurdles is the optimal choice and the maximum mixing indices were achieved at 45 degrees, 90 degrees and 22.5 degrees for two, three and four-hurdle setups, respectively. The Effect of varying aspect ratios of the channel cross section and radius and depth of the hurdles were discussed. It was concluded that the triangular chamber with a circular conducting hurdle is the optimal geometry configuration. Finally, this geometry was compared with a simple T-shaped electroosmotic micromixer and its time transient performance was checked. It was shown that exploiting these structures can both increase the mixing index and reduce the mixing time.