Abstract: One of the main obstacles to the successful utilization of compost in agriculture is the lack of reliable quality criteria and understanding the transformation of organic matter, which take place throughout the whole process. Proper evaluation of composts maturity essential for establishment of such criteria. Because of the diversity of origin of composts. It is impossible to use a single method to evaluate compost maturity. It is best done by a combination of methods. A good index of compost maturity should have an overall trend describable by a monotonic function. Methods for evaluating composts maturity can be categorized into (1) chemical analysis (C/N, CEC and nitrification) (2) physical analysis (odour and temperature) (3) spectroscopic analysis (FTIR and 13C-NMR) (4) plant bioassay (germination and plant growth) (5) chromatographic analysis (sephadex fractionation) (6) degree of humification (HI, DH and HR) (7) microbial analysis (respiration). These tests vary in precision, simplicity, costs, duration and approach. Plant bioassays are considered the most direct test for compost maturity since it shows the effect of compost maturity on plant growth and other maturity tests are correlated with plant growth performance. Spectroscopic methods, sephadex fractionation and degree of humification give an insight to the feasibility of starting material to be transformed, the level of humification and the quality of the humic fraction and the efficiency of a given composting process.