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Sieving and grading are two final operations of high quality grain production. Farmers in Iran normally winnow peas by hand, which leaves a large amount of debris among the peas. To correct this problem, a machine was designed and developed at Tehran University to second sieve and grade chickpeas. A low price, easy maintenance and usage, and technology appropriate for Iranian farmers were important considerations in the development of the machine. The following steps were taken during the design of the machine: Physical properties, terminal velocity, and coefficient of friction of five different varieties of Iranian chickpea:Jam, Philip, Bivanij, ILC-482 and ILC-12-60-31-- were determined. The following parameters and factors effecting machine operation were determined: sieve, number of sieves, shape and size of opening, sieve angle, oscillation stroke, angular velocity, volume of air entered, size and shape of air channel and fan size. The machine was built and evaluated. In the design and construction period, the variability, changeability, and adjustability of the whole system was observed. The sieve slope, sieve type, angular velocity, and air velocity of the machine can be altered, making it suitable for other cereal crops. The machine was evaluated with a flowing of known weight (2 kg), mixed, hand-cleaned peas (debris free) with 15 grams of known weight chaff and stem and 100 grams of clods and stones to determine its cleaning and grading ability, as well as overall efficiency. The arithmetic mean diameter was 6.7-9.7 mm with an average of 7.8 mm. The terminal velocity of a whole chickpea was 10-15 m/s, with an average of 12.6 m/s. For the dried leaves and stems, the averages were 3.0 m/s and 5.5 m/s, respectively. The minimum coefficient of friction occurred on galvanized steel with a 0.28 radian and the maximum coefficient of friction occurred on fiberglass with a 0.33 radian. The machine is capable of grading peas into four different classes: industrial use, human consumption, animal feed, and cultivation seed. The cleaning efficiency of the whole chickpea was 93 % and the debris was 94 %. Overall, machine efficiency was 84 %.