The Communist Party of China (CPC) has marked its birthday in a drastic and special way - forcing out one of its top former military officers and showcasing its slower membership expansion.

Both demonstrate the political courage of the CPC, the world's largest political party, to improve, purify and renovate itself based on sober judgement on the severe challenges and risks it faces.

The Party expelled four heavyweight officials, including Xu Caihou, former vice chairman of China's Central Military Commission, on Monday, a day before the 93rd anniversary of its founding.

Xu Caihou, file photo/Agencies

Xu is the latest among more than 30 high-ranking civilian and military officials downed in the country's anti-corruption campaign since the new CPC leadership took the helm in late 2012.

From merely 50-strong members at its birth in 1921, the CPC now boasts a membership of nearly 87 million.

The Party, however, on Monday announced the first annual decrease in newly enlisted members in the past decade and a 1.3 percentage points drop in the growth rate of its total membership.

The drop in new members results from the CPC's initiative to adjust its size and structure by enlisting members in a more prudent and balanced manner with the aim to improve quality and optimize structure.

In detailed rules for recruitment unveiled in late May, the CPC urged efforts to keep the Party's overall size in check and improve its structure and quality, following requirements raised at a meeting of the CPC Central Committee Political Bureau on Jan. 28, 2013.

To improve quality of existing members, the CPC has also been exploring ways to phase out unqualified members who have not infringed upon laws and Party regulations but whose conduct is nevertheless poor.

As China's ruling party, the CPC, which has excelled in revolutionary and peace time in the past 93 years, is now encountering long-term and complex challenges concerning governance, reform and opening up, market economy and external environment.

There are also pressing problems within the Party that need to be resolved, particularly corruption, incapability, being divorced from the people, and nonfeasance.

People's Daily, the flagship newspaper of the CPC, said in an editorial on Tuesday, "In revolutionary and war times, it counts for CPC members to charge the enemy lines and sacrifice, whereas what counts now is the wisdom for reform and governance capability."

To improve itself from within, the CPC has displayed its resolve to govern the party in a strict manner in the past 18 months from the anti-decadence campaign to the anti-graft fight against both high-ranking "tigers" and low-ranking "flies".

Compared with fighting in the battlefield, it is no easy job for Party members, especially officials, to stay clean, use their power in the right way and withstand various temptations.

The Party is facing the challenge with courage, wisdom and forceful measures to ensure its body remains healthy.