Introduction: Calcium critical limit in pistachio plants is about 1.3 percent of plant dried material; magnesium critical limit in pistachio leaves is about 0.6 percent of plant dried material. To measure calcium and magnesium there are several methods in which three methods of titration and atomic absorption that are more common and used to libraries more in addition to ICP modern method are used. This research was first performed all through the country and is so important because of using ICP system. Because This system is a modern method, very exact and expensive plus rare. This research uses forty samples of pistachio leaf’s extract. After preparing needed calcium and magnesium standards for every system, density of samples’ calcium and magnesium were measured. This research aims to obtain the most precious method of measuring plant calcium and magnesium elements after ICP system as possible and by the lowest experimental errors. Materials and methods: Extract of related plant was obtained by dry ash method and assimilation digestion by normal 3 chloride acid. Results and discussion: Regarding that ICP system method is the most precious and modern method, so this is a criterion and results of titration method and plant calcium and magnesium atomic absorption were measured to ICP system and rates of accuracy, deviations and measuring errors were determined.Conclusion: After measuring by ICP method, in this research titration by 97.65 percent accuracy (2.35 percent error) and then atomic absorption system by 93.13 percent accuracy ( 6.87 percent error) to measure density of plant calcium and magnesium are suggested.