Infometrics says exports to China are so strong because a cultural change there means demand is growing for New Zealand products.
Trade figures show exports to China last month were double the value of exports to Australia, contributing to the highest-ever overall trade surplus for a January.
Exports rose by 22 percent to $4.1 billion, driven by sales of milk powder, butter and cheese.
Infometrics economist Benje Patterson says it's not just dairy products in demand - there has been a broad-based increase in the price of many other goods such as forestry, meat, wool and wine.
He says the fact that exports to China are growing far more rapidly than exports to Australia is a sign of diverging growth patterns.
Mr Patterson says even though China's growth is slowing, there is a shift in China from investment-led growth to a model where consumption takes a central role - which means exports like meat and dairy will do well.
He says at the same Australia will not do as well under this framework because a lot of its key exports to China contribute to investment, for example, iron ore and coal.
Ultimately, says Mr Patterson, this should be more of a sustainable growth model for China, because instead of over- investment in excess capacity, the spoils of economic growth will be shared more equally among citizens.