Cook was accompanied by Terry Guo, founder and chairman of Taiwan tech giant Foxconn, and a number of Henan officials during his visit to the workshop. Cook was dressed in production line work clothes and shoe covers during the inspection.
He is currently visiting China to interact with top Chinese officials to allay concerns about its security
features of its data storage amid hacker attacks.
China is regarded as the biggest market for iPhone after US and expected to emerge as the number one in the coming years.
During the two-hour inspection, Cook listened to reports on construction of three Foxconn workshops in Zhengzhou and production of Apple iPhone products at the factories.
Though the Apple products are manufactured in China by Foxconn which also manufactures other rival brands like Smasung, they are sold in China after the global launch.
Cook's visit is aimed at supervising the production of its newly launched iPhone 6 at the Foxconn plants.
Foxconn's three workshops in Zhengzhou together employ three lakh workers and are dedicated to producing Apple's iPhone products.
Their output target for this year is 120 million iPhones, news agency reported.
Apple reportedly sold a record number of iPhone 5S handsets in China during October-through-December quarter in 2013.
About 16 percent of Apple's USD 37.4 billion sales in April to June quarter this year came from China, which is the world's largest smartphone market dominated by local Xiaomi and Samsung.
Apple products reported have little over six percent of Chinese market. According to reports, Cook noted at a conference call with analysts here that the launch delay for the new smartphones in China had an impact on the sale.
Iphone6 was launched far later than it was launched in US and elsewhere. He also attributed the sales disparity to inventory and said that in one respect iPhone sales actually rose in China.
"And so you have a compounded effect of no launch and a huge change in channel inventory in a year-over-year basis," Cook said on the call. "And to share with you what it was in greater China, iPhone unit sell-through despite no launch in Q4 was up 32 percent year over year.
The market was projected by IDC to only grow 13 percent. So we feel incredibly great about that," he said.