Activists complain that Kazakhstan has never held a fair election
Kazakhstan says it will put the main emphasis on security and development, rather than democracy, during its chairmanship of the OSCE.
Kazakh President Nursultan Nazarbayev said the Organisation for Security and Cooperation in Europe had for years been too fixated on Western values.
Human rights groups have criticised the decision to make Kazakhstan the first ex-Soviet head of the OSCE.
They say its record on human rights and civil liberties is poor.
They say Kazakhstan has never held a fair election and does not allow freedom of speech.
Rayhan Demetrie, BBC News, Almaty
Kazakhstan is the first post-Soviet country to head the OSCE. Inside the country, this is being represented as a major achievement on the international stage and a result of President Nazarbayev's wise policies. Those Kazakhs who are aware of the fact are proud. But the majority of people think there is no benefit to them.
Critics say Kazakhstan does not deserve to chair Europe's leading pro-democracy watchdog, because of the country's poor human rights record. The media is under tight government control, there is no freedom of assembly and not a single opposition party is represented at the country's parliament.
Kazakhstan has never held elections judged free and fair by Western standards.
In a video message to the OSCE assembly in Vienna, Mr Nazarbayev said: "The decisive question for the OSCE for the future will be whether it can convert into a structure that recognises the diversity of the world in the 21st Century, or whether it will continue to be an organisation segmented into blocs where the West remains aloof from the space 'east of Vienna'."
Mr Nazarbayev - who has ruled his country for 20 years - insisted that Kazakhstan was steadily building democracy and that "we will pursue further political liberalisation".
He said the priorities for Kazakhstan's year in office would include combating terrorism, resolving conflicts, and reconstruction in Afghanistan.
He also wants to call a summit of OSCE heads of government.
Foreign Minister Kanat Saudabayev told reporters at OSCE headquarters that Kazakhstan was no longer a totalitarian state and that it had "ambitious plans" for further democratisation.
"We believe that by chairing the OSCE in 2010, this will enable us step up the pace," he said.