The US-based rights group Dui Hua estimated that about 2,400 people were executed in China in 2013, and it says that number remained more or less the same in 2014 and 2015.
Last month, China's top legal official, Supreme People's Court President Zhou Qiang, claimed that executions in the country were now carried out in an "extremely small number of cases" and only for the "most severe offenses".
The world's top five executioners were China, Iran, Saudi Arabia, Iraq and Pakistan.
The study found out that generally across the world, death penalty was given to people whose crimes did not meet the criteria of "most serious crimes".
Amnesty's China-focused report, China's Deadly Secret, said for 2016, the group found 305 executions using a Chinese search engine, but only 26 of those cases made it to a national database. "In respect to death penalty it is leading in the worst possible way", said Amnesty International's regional director for East Asia, Nicholas Bequelin.
More than 3,000 people in 55 countries were condemned to death previous year, marking a 56 per cent surge from 2015.
The authors also note that drug-related offences do not belong to the category of "most serious offences" to which the death penalty should be restricted under worldwide law.
Salil Shetty, secretary general of the London-based global human rights watchdog, said the USA decline was "a sign of hope for activists who have long campaigned for an end to capital punishment".
Over the past few years the risk of people being executed for crimes they did not commit has caused increasing alarm among the public in China.
"When, shockingly, Bahrain executed three men after deeply unfair trials recently, the Foreign Secretary could muster only the mildest of rebukes".
For the first time since 2006, the U.S. was not one of the five biggest executioners, falling to seventh behind Egypt. "The size of death row was higher than expected".
Methods of execution used around the world included beheading, hanging, lethal injection and shooting. On the other hand, new death sentences had increased in 2016 to 3,117 from 1,998 in 2015.
But Hong said the website was never meant to provide a comprehensive database of executions and likely only includes verdicts meant to influence society or guide future trials. Meanwhile, 12 states, including Arkansas, yet to abolish the death penalty have not executed anyone for at least 10 years. But we have to fight to keep it that way.
President Xi Jinping, who has proclaimed his ambition to reform China's judicial system by making it fairer and more transparent, should turn his words into action and lift the cloak of secrecy that surrounds judicial executions. "The shocking number of executions scheduled over a ten-day period in Arkansas this April is a clear example of how quickly the picture can change", said Salil Shetty.
Uighurs accounted for about 4% of death sentences, despite accounting for only 0.7% of China's total population, according to a partial analysis of capital punishment data.
"The five isolated states that carried out executions previous year are behind the times". Belarus and Kazakhstan are the only two countries in the region to use the death penalty. Public executions were carried out in Iran (at least 33) and North Korea, the report added. At least 22 executions were carried out in five countries - compared to 43 executions in four countries in 2015.
While a majority of countries are moving away from the death penalty, India registered a major increase in death sentences imposed in 2016.
In sub-Saharan Africa fewer executions were recorded but the number of death sentences more than doubled, largely due to a steep rise in Nigeria.