Brazil is a country with several options of energetic matrices, due to its favorable climatic conditions, availability of land for cultivation of different cultures, oil reserves, amongst many other alternative sources of raw materials that can be used as fuel. Biodiesel is an example of energy used in the transport sector and derived from renewable sources, such as vegetable and animal oils and fats It is generally produced using methanol as transesterifying agent in homogeneous catalysis with a base. This type of catalysis, however, generates waste due to the need to wash the generated biodiesel, in order to meet the product quality standards. Therefore, there is a need to develop different production routes that are more economical and that use catalysts that are easier to separate and recover, enabling their reuse. In this work we studied the methyl transesterification reaction of soybean oil with the anion exchange resin, Amberlyst®, as a heterogeneous catalyst. This reaction was conducted using the 9:1 molar ratio of alcohol/oil, 50 ºC, ambient pressure and 300 rpm of stirring. We studied the effects of the load of catalyst used, reaction time, previous drying of the resin, and the amount of added solvent. The first experiment showed a peak of conversion rate using 2,5% of resin, by mass and in relation to oil, resulting in 1,04 ± 0,01% after 90 minutes of reaction. However, an increase was noticed when the resin was dried at 50 ºC, in order to remove residual water from its pores, obtaining the result of 2,42 ± 0,01% at the same reaction time of 90 min. For longer reaction times there was no considerable improvement in conversion. In order to verify the influence of the presence of cosolvent in the reaction, (n-hexane), four different amounts of it were used (mass ratio of cosolvent in relation to mass of oil was 0.5, 0.6, 0.8 and 1), keeping constant the other conditions of the reaction. All the proportions of cosolvent resulted in increased conversion when compared to previous experiments. The highest conversion obtained was 53,66 ± 0,02% using 0,8 mass ratio of cosolvent. In conclusion, we observed the necessity of drying the resin before it is used in the reaction, and that the use of cosolvent helps to increase the conversion. The analysis via MEV showed that the resin particle is spherical and that its surface is plain, without great variation when it was in natura or dried