Abstract:Abstract: Optimal fertilizer application with sustaining grain yield is a goal of modern agriculture development. Understanding the fertilizer application history of developed countries is helpful to provide lessons for fertilizer application in China. In this study, the concepts and calculation method of Fertilization Relative Output Rate (FRO), Yield Scale Coefficient (YS) and Fertilization Integrated Efficiency (FIE) were proposed to compare Fertilization Intensity (FI) and integrated efficiency of China and Euro-American countries of UK, Germany, France, Italy, Spain, US and Canada based on the data of fertilizer amount and grain yield in 1961-2017 from FAOSTAT. The FI was defined as ratio of fertilizer amount to harvested area. FRO was defined as ratio of Fertilizer Output (FO) to the maximum fertilizer output. FIE was the square root of product of YS and FRO and YS was the ratio of yield to the maximum yield of crops. The results showed that the FI value in China was increased rapidly with small fluctuation from 3.1 kg/hm2 in 1961 upon the peak of 338.2 kg/hm2 in 2014 and to 315.1 kg/hm2 in 2017. The FI values from 1961 to 2017 in five European countries of Spain, Italy, France, Germany and UK were in a similar pattern of "increase-decrease-increase-stable" and the peak values of these countries occurred in 1998 (169.0 kg/hm2), 1987 (235.0 kg/hm2), 1983 (438.3 kg/hm2), 1988 (503.4 kg/hm2), 1983 (594.9 kg/hm2), respectively. The FI values in US and Canada were slowly increased as immigrant countries with small fluctuations and reached peaks of 213.7 kg/hm2 in 1993 and 140.1 kg/hm2 in 2011, respectively. The FI values of eight countries fluctuated around 225 kg/hm2 (the internationally recognized fertilization safety threshold) between the range from 120 kg/hm2 to 350 kg/hm2. China, Canad and Italy had the highest FRO values respectively in the periods of 1963-1989, 1990-2001, 2002-2017, respectively, but the UK's values of FRO were mostly at the lowest level from 1963 to 2017. The rank of FRO values for eight countries after 2010 from high to low was Italy, France, US, Germany, Spain, Canada, UK and China with the average values of 0.99, 0.81, 0.67, 0.66, 0.62, 0.58, 0.49, 0.41, respectively. The Spain's FIE values were at most time below the other countries and they were rapidly increased before the end of 1980s and then became relatively stable. However, the FIE values of China and Canada were higher than the other countries respectively before 1990 and 1980, afterwards, they went down to the levels lower than that of France, Italy, Germany, US and UK. The FIE values of France, Italy, Germany, US and UK increased rapidly before 1990. They were increased slowly since 1990 but rapidly decreased since 2010. They showed increasing tendency in recent years. The FIE average values of eight countries in 2010-2017 ranked the first for France, then Italy, Germany, US, UK, China, Spain and Canada with average values of 0.88, 0.85, 0.81, 0.71, 0.67, 0.57, 0.54, 0.49, respectively. France was the best country in fertilizer use with high output rate, high grain yield and safety to environment. The average FI and grain yield in France in 2010-2017 was 207 kg/hm2 and 7 294 kg/hm2 and the FI was less than 225 kg/hm2. France could be considered as a good example for China to learn from in decreasing fertilizer use amount while sustaining grain yield in eco-agriculture construction.