Held in the Chinese capital city of Beijing, the meeting is closely watched for signs of policy shifts in the world's second-largest economy.
Even though the meeting is a major national event that is well-publicized — it has a dedicated website and has been trending topic for days on Chinese microblog Weibo — proceedings are shrouded in secrecy.
The Party Congress will close on October 24 this year, after which the new leadership will be announced.
In short, it's a meeting to vote on the leadership of the Communist Party of China. Held every five years, the event's duration is not officially reported, but the last Congress ran over eight days.
About 370 full and alternate members of the party's elite Central Committee will be elected at the Congress. Full members have voting rights and they all come from a pre-selected pool of candidates.
They are chosen by 2,287 delegates from diverse backgrounds and groups. Among them are farmers, professionals and academics.
Those participants have been pre-screened and are deemed to have "unshakable belief," "correct political stance" and "good moral quality," among others, according to state-owned China Daily. The Chinese Communist Party boasts a membership of 89 million.
At its first session, the new Central Committee will elect about 25 members of the powerful Politburo
The Politburo will then choose members of its Standing Committee, China's top leaders. The group — now headed by President Xi Jinping, who is general secretary of the Communist Party — will be unveiled next Wednesday.
The Congress is more about ideology than policy, but it still charts the future direction for China and offers a glimpse into its opaque politics.
At the 12th Congress in 1982, "Paramount Leader" Deng Xiaoping heralded in the age of China's socialist market economy that propelled the previously impoverished country into the world's second largest economy in just three decades.
At the 17th Party Congress in 2007, Xi was appointed to the Politburo Standing Committee, which signaled to the world that he was primed to take the top spot in the country's leadership.
Five years later, Xi took office as the general secretary of the Communist Party. He became president of China in 2013.
Xi is expected to consolidate his power and remain at the helm. Described by observers as the most powerful Chinese official in decades, Xi last year was recognized as only the fourth person to earn the designation of "core" leader.
China watchers are looking for an amendment in the party constitution at the end of the congress that will incorporate Xi's ideological doctrine in the charter.
Some have even projected that the meeting will effectively appoint Xi as "emperor for life."
There's little transparency into the process, but most outside observers say the congress is a largely scripted affair. Still, the lead-up to the meeting has been rife with speculation over the behind-the-scene political jockeying.
The opacity over the meeting proceedings, however, is contributing to some concerns on the markets. That said, most analysts aren't expecting major developments that will significantly shake up economic forecasts or financial bets.
The number one thing to watch is Xi's tightening grip on authority. But that might not be very exciting, as it's been deemed a virtual certainty that he keeps his position and cements influence.
Next up for China watchers is Wang Qishan, who at 69 years is above the unofficial retirement age. The Xi ally played a pivotal role in the president's anti-corruption campaign (which some have alleged was simply an elimination of rival intra-party factions).
Although Wang would normally be expected to retire given his age, many have suggested the retirement norm could be extended to accommodate another term for him on the Standing Committee.
Premier Li Keqiang's job is also on the line, with some suggesting that Wang may replace the economic czar.
Geopolitical consultancy Eurasia Group, however, said that's unlikely.
"We believe Li remains premier because he and Xi roughly share the same vision for China's economy and work reasonably well together, despite a lack of personal chemistry. Also, removing Li would be risky and disruptive at a time when China needs stability and continuity," Eurasia said in a recent note.
What is more likely is that Wang steps down from the Politburo Standing Committee but continues to play a policymaking role, said Eurasia.
The other major point of interest for the meeting's announcements will be whether a younger official is elevated to a station that makes them a prime candidate to replace Xi.
Although it has been the norm of late for a leader to begin grooming a successor in his second term, some analysts are predicting that Xi will buck the trend and keep his authority to himself — potentially setting himself up for a third term.
— Reuters contributed to this article.