Assessment of the B0 inhomogeneity of a micro solenoid of a 1mm diameter at 9.4T and comparing the performances of methods are used for reducing the B0 inhomogeneity in MR Microscopy. The solenoidal coil is made of a gold copper wire wounded on an SU8 cylinder which is used as a sample holder [1]. Figure 1 illustrates the geometry of fabricated and simulated coils design. Table 1 depicts the geometry and magnetic susceptibility factors of the coil elements and the used sample [1,2].Simulation of B0 magnetic fields of a solenoid micro coil of 1mm diameter was performed inside a doped water sample according to magneto static equations by using Comsol and Matlab. To reduce the B0 inhomogeneities across the sample, two procedures were followed; applying the shimming fields and embedding the coil in a susceptible material;. For applying the shimming fields, at first the B0 field inhomogeneity was calculated across the sample. Then for minimizing the inhomogeneities, the shimming coils currents were optimized using least mean square (LMS) algorithm. Susceptibility matching method was performed by embedding the coil in a susceptible material. And the optimal magnetic susceptibility factor of the surrounding material was obtained by minimizing the B0 fields deviation using LMS algorithm.B0 maps were obtained using phase difference method according to Δω₀ =ΔΦ/ΔE [3]. where, In this equation, ΔΦ and ΔE are the phase and echo time differences of two 3D GE images. The phase difference of two images were derived from the phases of the Fourier transformed (FT) images at two different echo times. Then the phase data were unwrapped using a custom made program written in Matlab. Images were acquired using a solenoidal microcoil ( see Fig. 1) from a water doped with cu₂so₄ sample at 9.4T Bruker Biospin 94/20 system.Figure 2 compares the 2D B0 simulated and measured maps of a solenoid of 1mm diameter which its elements geometries given in table 2. Results show that the maps are in good agreement and standard deviation (STD) of simulated and measured data are 125.1 and 118.2 Hz respectively. Considering this agreement, some simulations are performed to reduce the magnitude of B0 deviation across the sample. As a first step the length of SU8 increased to 5 mm. Simulation results show that increasing the length of the sample holder of about 8 times will decrease the STD of B0 deviation to 40.8 MHz. As it is expected this result caused by increasing the aspect ratio (or ratio of length to diameter) of the SU-8 cylinder. Then the solenoid was embedded in a susceptible material with the optimized susceptibility factor of -35×10-6 (such as the epoxy doped with Er ³⁺ ) and then 2D B0 maps were produced across the sample. Table 2 depicts that the STD of the B0 maps has drastically decreased to 0.3 Hz. Finally we calculated the optimal shimming magnetic fields using LMS method and then applied them to the sample and coil geometry. Table 2 represents that this procedure decrease the STD of the B0 deviation to 23.3 Hz.We measured and simulated 2D B0 maps of a solenoid of 1mm diameter and verified that there is a good agreement between the measured and computed results. Then considering this agreement, to reduce the B0 inhomogeneities of the microcoil three methods were evaluated in the simulation environment. Simulation results show that, although, applying the shimming fields and lengthening the coil can decrease the magnitude of B0 deviation significantly. However, the susceptibility matching method can almost fully remove the B0 inhomogeneities of the micro coil.