Basic characteristics of the electronic devices are able to figure out from V-I characteristics. V-I characteristics analysis is available for observational study in the semiconductor devices, because this method is able to use a number of times without destructive. Much information is able to get from this method in many variant conditions, and this information has data of the internal constitution of semiconductor devices. The results of V-I characteristics measurement and parameter analysis from the semiconductor junction of between B and E terminals on transistor show that internal resistance“R” increases in low current range, and“R”has 3 values pattern. These phenomena arise from carrier density and the internal constitution of semiconductor devices. These results of analysis show that this studying method is quite useful as the internal constitution study in the semiconductor devices. In the future, this studying method will bring the expected results with new functional capability temperature, stress and exposure to light.