Recognition and determination of self-refinement power of the rivers is essential to correctly management the assignment of pollution releasing license to rivers. In this respect, study of mass transferring and mixing processes in the rivers is very important for water resources management planning. Complete mixing length is one of the most important factors for determination of self-refinement power of the rivers and transverse mixing coefficient consider as the most significant parameter for complete mixing length calculation as well. The impact of factors affecting transverse mixing coefficient was currently studied by many researchers. In this study, the effect of simultomous use of vegetation besides local block on transverse mixing coefficient was evaluated in the first phase. In the second phase, the effects of channel width changes based on the depth considering vegetation and local block existence on transverse mixing coefficient was assessed. The vegetation used in the study was polyamide filaments with 0.036 density and the local blocks were rectangular blocks with the 2, 2.5 and 3 cm heights which put on the bottom of the channel in three rows with 10 cm distance from each other. Thus, nine experiments were carried out at the first phase using experimental rectangular channel with 8m length, 0.4m width and 0.6 m height having maximum discharging of 50 l/s located in Isfahan University of Technology Water research Institute. All the experiments had constant depth (26 cm) and flow rate (17.4). The detector was sodium chloride with concentration of 25 gr / l. The concentrations were measured at four sites and 15 points in each site located at downstream of injection spot. The transverse mixing coefficient for all experiments was calculated through the simplified terms of mass preservation equation. An experiment was carried out without the vegetation and local block to create a basis for other experiments comparison. An experiment was done using vegetation lonely and another experiment was performed only with the local block. Several arrangements of vegetation and local blocks were also evaluated in six experiments and the transverse mixing coefficient was calculated for each one. The results demon traded that the best arrangement for increasing the transverse mixing coefficient and decreasing the complete mixing length belonged to alternate arrangement of vegetation and local block () with the vegetation primacy. In this arrangement the efficiency of mixing length decrement compared to control experiment is about 67%. Three arrangements of (%56.7), (%56.4) and (%51.8) had the next best results. Assessing the flow status on different experiments indicated that shear rate, Reynolds shear tension and turbulence intensity have direct correlation with transverse mixing coefficient while the vertical rate has the inverse correlation. In the second phase, the effect assessment concinnity/transverse mixing coefficient ratio indicated that this ratio value decreased by increasing the width/depth ratio in constant rate. Keywords: Transverse mixing coefficient, vegetation, local roughness, complete mixing length, concinnity ratio