This paper presents graphical optimization method of LC voltage controlled oscillator (LC_VCO). This method accomplishes with optimum size of LC_VCO components. This oscillator is characterized by tuning range of 4% from carrier frequency centered in 4GHz. The phase noise is -126dBc/Hz at 1MHz offset frequency from carrier frequency of 4GHz and the power consumption is 11.6mW from a 2.5V supply voltage. Theory approximations by graphical optimization method are verified by simulation.