Abstarct: Blasting operation is One of the most important parts of open pit mining cycle. The aim of this operation is fragment of ore and waste to appropriate dimensions and transporting them to out of the mine area. The consequences of blasting directly affect the mining costs and efficiency of haulage system. Delay times is one of the variable parameters that affected blasting achievements. The importance of determination of this parameters is because of its affection on the several items such as muckpile geometry, back break and also the mine haulage system in addition to rock fragmentation. In this research ten blasting on the north heap of Chadormalu iron mine has been studied. This blasting operation carried out in the same conditions and different delay times in order to recognizing the influence of this times on the consequences of blasting and mine haulage system efficiency. After the analyzing of the results of blasting from several aspects such as rock fragmentation, muckpile geometry and back break, the influence of this items on the loading and carrying machinery operations has been evaluated. baxsed on the analyzing of results the most proper rock fragmentation has been obtained in the delay times range of 130 to 150 msec that caused improving the efficiency of haulage system. This range of delay times also caused the most appropriate muckpile geometry that improves the operation of loading and then carrying machinery. Utilizing of upper delay times for safe work environment including walls stability for loading and carrying machinery is more appropriate because of reduction of back break baxsed on results analyzing. As the result the delay time range of 130 to 150 msec has been offered for blasting of this heap because of appropriation of rock fragmentation and muckpile geometry that improves the operation and efficiency of haulage system of north heap of chadormalu iron mine.