The Communist Party of China (CPC), the world's largest political party, witnessed a slower membership growth rate last year as the Party began to enlist new members in a more "prudent" and "balanced" manner.

The CPC had 86.69 million members at the end of 2013, up 1.8 percent year on year, according to figures from the Organization Department of the CPC Central Committee.

The growth rate was 1.3 percentage points down from the previous year, said a department statement on Monday, one day before the 93rd anniversary of the CPC's founding.

Last year, 2.41 million people joined the Party, 825,000 less than in 2012. The net increase was 1.56 million.

This was the first annual drop in newly enlisted members in the past decade.

The CPC enlisted 2.42 million new members in 2004. The number continued to grow in the following years until it reached 3.23 million in 2012.

"The drop in new members results from the CPC's initiative to adjust its size and structure with the aim to improve quality and optimize structure," said Xin Ming, professor with the Party School of the CPC Central Committee.

The CPC published detailed rules for recruitment in late May, requiring all localities and organizations to enlist new members in a "prudent" and "balanced" manner.

The rules stipulate that efforts should be made to keep the Party's overall size in check, to improve its structure and quality, following requirements raised at a meeting of the CPC Central Committee Political Bureau on Jan. 28, 2013.

"It is absolutely not the case for a political party that the more people the better," Xin said.

"The CPC is a vanguard organization, so it must be strict in its recruitment to select the best and secure the exemplary and vanguard role of Party members," he said.

At its birth in 1921, the Party only had about 50 members. This grew to nearly 4.5 million when the People's Republic of China was founded in 1949.

The number of the Party's grassroots organizations grew last year with their presence in private companies and social organizations further expanding, according to Monday's statement.

The CPC had more than 4.3 million grassroots Party organs across the country by the end of 2013, up 2.4 percent from a year earlier.

Party organs have been set up in nearly 1.63 million private companies, accounting for 58.4 percent of the national total, up 4.1 percentage points from the previous year.

About 110,500, or 42 percent, of the country's social organizations had established Party organs by the end of 2013, up 6.8 percentage points year on year.

In addition, more frontline workers, women, people from ethnic minority groups, as well as younger and more higher-educated individuals joined the Party, according to the statement.

Of the total membership, 24.3 percent are women, up 0.5 percentage points and 5.95 million, or 6.9 percent, are from ethnic minority groups, up 0.1 percentage points.

The CPC has 22.38 million members who are 35 years old or younger and 36.07 million have obtained degrees in higher education institutions, up 0.2 and 1.6 percentage points respectively, according to the statement.

Professor Xin Ming believes a political party must allow flow of its members to ensure vitality. "The CPC should apply strict control over membership while improving quality of existing members by enabling the unqualified to drop out."

Ways to handle unqualified Party members have been explored.

In an overhaul of the nearly 220,000 CPC members in Yichun City in east China's Jiangxi Province, which started in April 2013, 674 were classified as unqualified and 114 of them were expelled or told to quit.

"Some people's discontent towards the CPC might only stem from an unqualified Party member around them," Xin said. "So finding ways out for unqualified members is necessary and must be dealt with earnestly." Endite