The collection of internal taxes is a tool that empowers SUNAT to adopt the necessary measures to generate the highest tax revenue from Peruvian source income, activities carried out by taxpayers. The present investigation called "Analysis of the evolution of the Internal Taxes collected by SUNAT through Peruvian source income, period 2016-2020”, has the general objective to determine the evolution of the internal taxes collected by SUNAT through the Peruvian source income, 2016-2020 period. Likewise, the research was of a quantitative type and of a descriptive, non-experimental - transversal design. From the analysis and discussion of the results obtained, it was determined that internal taxes show an evolution with a negative trend in the last year.