Abstract: The method of recording manually which recorded values of absorption in the general spectrophotometer can't be a pplied to being recorded accurately its values of spectra, especially converting tinge solution between 10^-5 mol/L and 10^-4 mol/L. It results in becoming accurate and sensitive lowly. However, it a voided this deviation, which is applied by spectrophotometer connected to a computer, and its accuracy and sensitivity is very high and keeps good linear relation, and automatically plots the graph which is obeyed by Beer's law and outputs the graph, and its device is simple, rapid and direct with successful result.