Former British Prime Minister Tony Blair in his congratulatory message referred to the CPC congress as a gathering that could reflect on the remarkable progress China had made in the past five years.
There were numerous challenges and opportunities that all countries faced, many of which could only be tackled through partnership and cooperation, the message said, stressing "on all the big issues, we need China to be a partner for progress."
"So whether the issue is global economics, climate change, Africa world trade or securities questions, countries around the world, together with China should create the circumstances for strong partnerships," the former PM said.
Mari Bin Amude Alkatiri, general secretary of the Revolutionary Front of Independent East Timor and former prime minister of the country, said the congress was of great historic significance for the CPC, China and the world.
Nikolai Levichev, leader of the Russian Justice Party, said the congress, a historic event for the CPC and the Chiese people, would score fruitful achievements and help China achieve more success in internal and international affairs.
The Liberal Democratic Party of Russia said China, as the most populous country in the world, had maintained rapid development in various fields and realized stability and prodsperity.
The Communist Party of India (Marxist) said in a message it had been keenly following the developments taking place in China and noted the impressive economic advances made by the country.
It was confident the relations between the peoples of China and India would continue to improve and contribute to bringing peace and stability in the region, the message said.
S. Suoakar Reddy, general secretary of the Communist Party of India (CPI), said his party noted the Chinese people in the past five years had already registered tremendous progress in all areas through implementing a scientific outlook on development aimed at achieving social harmony and balanced growth.
"We have much expectation and hopes about the outcome of the 18th Congress of the CPC, which we are sure will further strengthen the resolve of the Chinese people to build socialism with Chinese characteristics," he said.
The Director of the Presidential Office of Belarus said, under the leadership of the CPC, China had scored remarkable achievements in all fields and was playing an important role in international politics and the economy.
Joseph Ejercito Estrada, former president of the Philppines, said there was no doubt the accomplishments of China had been remarkable, with the impressive growth of its economy.
The new leardeship would play a critical part in steering the nation to reach its goal for thje next decade, he said.
Walid Jumblatt, president of the Social Prograssive Party of Lebanon, said the world expected China to have greater achievements that would serve as a model for others.
Secretary General of the Yemeni Alliance For Reform Abdul-Wahab Ahmed Al-Anqsi, in a message, wished the CPC congress a success.
The message said the alliance believed the CPC would continue to push forward the reform and opening-up process and strengthen institutional and capacity building of the party, continuously lift China's international status, support developing countries and make contributions to maintaining world peace.
The Egyptian Communist Party Central Committee said the CPC congress was of special significance as it was convening against the backdrop of major changes in the world.
First alpine rail gets midnight maintenance