Mechanical vibration is the easiest and cheapest way to enhance properties of the castings, such as mechanical, electrical, chemical. Also, chemical agents such as grain refiners could assist to improve the casting properties. In this study, coupled actions of mechanical vibration and grain refiners were applied to the castings to investigate the electrical conductivity of Al7Si0,3Mg (A356) aluminium alloy. Grain refiner, Al5Ti1B, was added to Al7Si0.3Mg alloy in the form of three different addition of 0.1, 0.2, and 0.3 wt.%. The castings were carried out with and without grain refiner on vibrational casting technique. Another investigation of this study is to demonstrate the effect of excess grain refiners on the microstructure having solidified under vibrational forces. The results were evaluated by means of electrical conductivity with Weibull Distribution, and SEM micrographs. Reliable and reproducible results were found in the middle section of 0.1 wt.% Ti grain refined samples which had a Weibull Modulus of 512 and 33.73 IACS%. It is demonstrated that vibrational casting has no effect on the distribution of grain refiners in the microstructure.