Hot tearing is a common defect which occurs during solidification of cast alloys with large mushy zones. Determination of hot tearing tendency and the effective parameters are of great interest to researchers in this filed. In the present research a two step process for determination of hot tearing tendency is introduced. The first step includes the design and manufacture of an apparatus for measuring the required physical and mechanical data needed in the second step. The second step is utilization of a new proposed hot tearing criterion named NNC which incorporates both mechanical and metallurgical parameters. NNC was validated using A206 aluminum alloy, a very hot tearing prone alloy, through changing such casting parameters as super heat temperature (with and without grain refinement), percentage of grain refiner, copper and gas content of the melt. The results were analyzed by NNC, load rate and Davies criteria. The results showed that NNC could more consistently predict the experimental results obtained and had higher precision than other criteria. This seems to be due to simultaneous utilization of both mechanical and metallurgical parameters by NNC which enables it to give a more realistic picture of the concurrent effects of several variables. The results also showed that the hot tearing tendency of A206 alloy increases with an increase in melt super heat. Although, addition of grain refiner at high super heat could not effectively refine the microstructures, it decreased the hot tearing tendency by slightly changing the grains morphology. The optimum percentage of grain refiner for reducing hot tearing was recognized to be 1%. Increasing copper content from 4.45 % to 5.1% reduced hot tearing tendency. Furthermore, hot tearing tendency was increased by degassing because of increased contraction and reduced feed ability of the melt. Key words: Hot tearing susceptibility, NNC, A206, Supper heat, Grain refinement, Cupper content, Degassing