A deputy governor of China's central bank recently unveiled a major economic milestone in a rather casual manner.

"China is actually now already the world's second-largest economy," Yi Gang, who is also head of the State Administration of Foreign Exchange (SAFE), said in an interview posted on the SAFE website last Friday.

The milestone was an expected accomplishment, as it has been a consensus shared among economists, politicians and the media that China would sooner or later become the world's second largest economy. The only question was when the milestone would occur.

Following Yi's remark, some media lauded China's leaping forward and to a certain extent, exaggerated its significance.

Of course, becoming No. 2 in the world is a milestone earned after decades of hard work by the Chinese people.

Thanks to the reform and opening-up policy, China has experienced uninterrupted economic ascent over the past three decades, overtaking Britain and France in 2005, Germany in 2007, and now Japan.

However, it is also important to ask ourselves what it really implies to become the "world's No. 2 economy," and then stay cool.

After all, China's per-capita gross domestic product (GDP) is still far behind that of many other countries including, of course, Japan.

According to the World Bank, China's per capita GDP was a bit more than 3,600 U.S. dollars in 2009, ranking 124th worldwide, whereas Japan's per-capita GDP amounted to over 39,000 dollars.

Indeed, China's current per capita GDP is equal to only that of Japan in 1973, which was at around 3,800 U.S. dollars.

Analysts forecast it would be not until 2050 that China's per capita GDP reaches the 2009 level of the per capita GDP of developed countries.

In short, China has a long way to go.

"China is still a developing country, and we should be wise enough to know ourselves," Yi has said.

With an economic structure far from perfect, China still faces numerous challenges, such as additional work on the balance of its development and the growth of its scientific innovations and high value-added industries.

China is obviously behind Japan in the process of economic development. The shares of agricultural, industrial and service industries in Japan's overall economic pie stand at 2 percent, 30 percent and 69 percent, respectively. That compares with China's 12 percent, 48 percent and 40 percent.

Japan draws its strength from high-tech and high value-added industries, whereas many of China's industries are labor intensive.

Gross national product (GNP) can often be a better gauge of the overall economic strength of a nation. Statistics show that China's GNP was around 4,129 billion U.S. dollars, while that of Japan was more than 5,751 billion dollars. China is even farther behind in per capita GNP.

China has to re-adjust its economic structure and change the models of development to have growth quality and efficiency, Yi said.

We should also beware of the pressure and demand on China for unrivaled responsibilities advanced by certain media and politicians, who have spoken loudly about China's overall economic size.

Several western media recently slapped China on energy consumption, emissions and what they see as an exchange rate policy issue. They also demanded that China take on more political and international responsibilities, such as climate control, that are beyond the country's capacity.

By exaggerating China's rise, some are also attempting to stir up the concerns or even hostility of neighboring countries against China.

GDP is never the only gauge of a country's economic strength, and therefore is not a justified measure of responsibilities either.

The rise of the Chinese economy poses no threat to the global economy. Instead, it brings more benefits and opportunities to the world at large.

ViVek Arora, the IMF's chief representative in China, has said that since the world economic crisis in 2008, China has made the biggest contribution of any single economy to global economic growth.

The biggest developing country, China has actively taken on its due responsibilities. It has provided huge assistance and help to other developing countries, especially less-developed countries.

A prosperous Chinese market also provides more opportunities for the global economy, its neighbors in particular.

On Jan. 1, the Free Trade Area agreement between the Association of Southeast Asia Nations (ASEAN) and China took effect, boosting trade and economic cooperation between the two sides.

In the first half of this year, trade between China and the ASEAN surged 55 percent to 136.5 billion U.S. dollars.

The Moscow-based weekly The View has a keen observation on China's economic growth.

"It is wise for China to recognize that it still remains a developing country," the newspaper said.