Abstract: In many arid areas of the world, the waste water of the cities is considered as one of the valuable and revivable sources of water. Sewage purification, in addition to environmental preservation, helps to recover the water for us to use it again. Considering the shortage of water and the cost of water sources recovery and purification, we can use the waste water that remains after the purification of cities sewage and industrial sewage for different uses. This kind of reusing the waste water depends on the quality and the quantity of sewage, grade of purification, cost of purification and the environmental rules and standards. In this study, the researchers tried to measure the efficiency of a mixture of the Plantago Major powder, Alyssum SP, Plantago Psyllium and Zizi Phora Clinopodioides in comparison with aluminium sulfate efficiency in the course of purification. In carrying out the experiments, the city sewage with the average level of impurity have been used. The coalescence experiments have been done by the Jar machine and the sewage quality parameters have been measured by the methods described in the Standard Method book. Surveys have shown that in the optimum density of the four seeds the percentage of removing turbidity, total solidity, Calcium solidity, Magnesium solidity, the total Coliform and Ashrshya are equal to 99.5, 65, 61, 90, 95 and 94, respectively. Regarding the results, we came to the conclusion that the mixture of 30 mg L^-1 of the four seeds powder with 20 mg L^-1 of Alum is more efficient than other kinds of attendance. One of the most important advantages of using the four seeds powder in comparison with Alum is the reduction of sedimentation time from 30-10 min. Considering the results of surveys, we can mention that the sludge volume resulted from the four seeds powder is less than the sludge volume resulted from the Aluminium Sulfate and also dehydration of sludge resulted from the Aluminium Sulfate is more difficult and more time consuming than dhydration of the sludge resulted from the four seeds powder.