Acid fracturing is one of the eligible techniques for increasing productivity of hydrocarbon reservoirs. The acid fracturing process consists of two stages, fracture creation using a viscous fluid and acid injection into the fracture. Since a fracture formed by hydraulic fracturing or acid fracturing before acid etching has a tensile rough fracture, using a smooth fracture surface may not represent the actual fracture condition. Therefore, In this study acidizing test were performed into rough fracture. Statistical and spatial distributions of apertures may be changed due to chemical dissolving. The chemical dissolving in rocks may be due to the passage of acidic water through fractures or acid fracturing treatment. In this study, an acid injection cell was developed to simulate acidizing stimulation into fractures and investigate fractures surfaces etching and aperture evolution due to acidizing. The tests were performed on hard limestone with low permeability from the Asmari formation (one of the oil reservoir formations in Iran). Conductivity of fractures in low stresses was determined using permeability test. In the case of high stresses, conductivity was determined using a penetration model and local aperture (derived from surface scan) and a numerical finite element code developed in MATLAB. Measuring normal deformation of fracture emergent from applied normal stress showed that longer durations of acid injection exhibit more normal deformation and lower final conductivity. Results showed that increase in the initial roughness coefficient and the linear roughness of fracture surface resulted in higher surface etching and higher dissolved rock equivalent conductivity (DREC). With increase in fracture surfaces mismatch, fracture aperture and eventually initial fracture conductivity also increase. Initial hydraulic and mechanical apertures and permeability (under zero stress) are increased due to fracture acidizing and a varying range of 2% to 12% contact area was observed. Apertures before and after fracture acidizing followed a log-normal distribution. Correlation length increased in the direction of acid flow ( x -direction) after acidizing. Results of fluid flow modeling using a developed finite element code showed a channeling path in the x -direction. Furthermore, using fast sequential simulation algorithm, apertures with various spatial correlation length in x and y directions are generated. Numerical modeling results of these generated aperture patterns showed that flow channelizing is increased by increasing of correlation length in the x -direction. Fluid flow rate is increased with increasing of correlation length in x -direction, while it decreased with increasing correlation length in y -direction