Ni said data from two Beijing courts showed the number of death sentences resulting in immediate execution had dropped 10 percent.
He added the picture was similar across the country.
"If a case is sent back for retrial by the highest court, it not only means the first judgement is wrong, but also a matter of shame for the lower court," he said.
The report also quoted Chen Weidong, an expert on criminal law with China's Renmin University, predicting the number of death sentences would drop by 20 per cent by the end of the year.
|All death sentences must now be |
reviewed by the supreme court [EPA]
"Leniency and more judicious use of capital punishment is the trend of the time, a concept in line with international practice," Chen said, according to Friday's report.
The newspaper did not give figures on the total number of executions across China, in line with the government's long-held policy.
A recent report by Amnesty International estimated that at least 1,010 people were executed in 2006 while 2,790 were sentenced to death.
However, Amnesty says it believes the true number of executions to be much higher.
China's criminal justice system "cannot and does not guarantee a fair trial under international law to defendants," the human rights group says on its website.
In recent years, Chinese media have exposed a raft of cases of miscarriages of justice which resulted in death sentences, causing widespread condemnation of lax practices by local courts.