Composting has historically been carried out by farmers for manure management, which is a reliable way to recycle manure for use on croplands in sustainable agriculture. However, poor management of the composting process can result in un-mature compost product, which inhibits plant growth and deteriorates soil condition. The seed Germination Index (GI), an authoritative parameter to evaluate the maturity of compost, has been widely utilized in evaluating the phytotoxicity and other aspects of composting process. However, there are still lack of unified standards for the measurement method of GI and the representative type of experimental seed until now, which leads to the diverse results of GI (fluctuated from 20%-217%), and the newest standard of organic fertilizer (NY525–2021) requirements GI≥70% of organic fertilizer. Thus, it is meaningless to compare these values between different studies in related fields and urgently for public to provide a reference measurement process for GI during composting. Therefore, this study protocoled four treatments, composting chicken manure with or without auxiliary material (carbon additive) for different phytotoxicity compost, and selected four types of seeds for sensitive assays according to previous studies, mainly included cucumber, radish, Chinese cabbage and oil rape. Besides, in the process of germination experiments and indexes calculation, detailly instruction for the whole process of GI determination and calculation was documented, which stipulated the definition of radical length for 0, 1 mm and the start position for measure (with diagram). Furthermore, systematically detecting the response relationships between influenced parameters and GI of different composting treatments. The results showed that, according to the GI of final compost, the maturity increased in the order of pure pig manure treatment (26.54%-80.49%), pure sheep manure treatment (16.71%-92.98%), pig manure and straw treatment (28.28%-110.74%), sheep manure and straw treatment (43.38%-119.69%). Carbon additive of straw could significantly improve temperature of composting systems and further maturity of the final products. Increasing pH and decreasing phytotoxicity of electronical conductivity, low molecular organic acid and organic matter contents at the same time. Seeds’ GI decreased with the order of radish (≤130%), cucumber (≤100%), oil rape (≤70%), Chinese cabbage (≤45%). The sensitives were reflected with correlation analysis, which between physical and chemical indicators (temperature, oxygen, pH, carbon and nitrogen ratio) and biological toxicity factors (electronical conductivity, ammonium nitrogen, organic acid and organic matter) and GI with different seeds (cucumber, radish, cabbage, rape) of four composting processes, and fond the factors influenced GI with the sequence of NH4+, pH value, O2, VS, VFAs, EC, C/N, temperature, which was in accordance with the affected sequence of radish seed. Besides, radish seed showed the highest responsivity (3.69, r=0.96) of GI for influenced factors, which was the most scientific and representative type of seeds for comprehensively reflecting maturity and phytotoxicity of compost of discrepancy qualities compost. Furthermore, radish has been widely studied for the reasons of fasting germination speed, moderating molecular size, obtaining easily and lowering price. These results can provide scientific references for the determination and comparation of GI, the establishment of organic fertilizer standards and the safe application of compost in farmlands.