Concerns on environmental issues associated with application of raw manure in agricultural lands have forced farmers to find out alternative options. Rapid decomposition of nitrogen contaning organic compounds in the raw manure results in the release of ammonia and its accumulation around plant roots. The composting process offers the potential to significantly reduce environmental problems and agronomic limitations associated with raw manure management. On the other hand, the cost of composting can be greatly higher than raw manures. Therefore, composts with higher quality attributes must be produced to offset these production costs. To improve quality of compost, knowledge on the rate of nitrogen mineralization and chemical properties of manure during composting is necessary. Chemical and physical properties of compost such as temperature, water content, pH, carbon to nitrogen ratio, and microbial respiration play key role in composting process. In this research study, the effect of C:N ratio, season, and areation practice of windrow on chemical and physical properties of composted manure was investigated. This factorial experiment was conducted in a complete blocks design with three C:N ratios of raw materials and two areation treatments at two different seasons. Manure was amended with different amounts of sawdust to produce final C:N ratios of 1:20, 1:25, and 1:30. Initial water content of compost was kept about 65% w/w. Constant temperature of compost for five consequesnt days was considered as an index to identify maturity of compost and the end of composting process. Samples were collected from the depth of 75 cm of the windrow. There was no significant difference beween winter and summer seasons in chemical properties of composted manure. A major problem in composting process of manure was significant loss of nitrogen, more than 43% of initial nitrogen was lost during the composting process. The C:N ratio decreased at all C:N treatments over time. The EC of the compost also decreased over time. The pH of composted manure increased to about 7 at the end of composting period. This can also be used to indicate the maturity of compost. The ammonium concentration of compost significantly decreased over time due to leaching and volarilization of ammonium. The micrbial activity greatly reduced after 14 days and then remained constant. According to the results obtained, regardless of the season, the highest and lowest pH, organic matter content, volatilization of ammonium, and nitrogen loss was observed at the C:N ratios of 25 and 30, respectively. According to the results, at winter season, pH, microbial respiration, and loss of ammonium was greater at with areation treatment compared with without areation treatment. Also, EC, loss of organic matter, and loss of nitrogen was lower at with areation treatment than without areation treatment. Keywords: Chicken manure, composting process, C:N ratio, microbial respiration, areation, organic matter