This was reflected in Apple's earnings release last month, when it said it booked $13 billion in revenue from China during the quarter, down 27 percent from the year-ago quarter. Overall, Apple said iPhone revenue fell 15 percent.
Apple revised its guidance ahead of that report in early January, when it said a weakening economy in China and the strength of the U.S. dollar were to blame for weaker-than-expected iPhone revenue.
Huawei ate up Apple's shipment losses in China, where its shipments increased 23.3 percent during the same period. Other local phone makers including Oppo and Vivo saw shipment gains of 1.5 percent and 3.1 percent, respectively.
"In addition to the regular performance upgrades in 2018, there is no major innovation to support users to continue to change their machines at the greatly increased price," IDC said. "At the same time, under the impact of China's severe macro environment and domestic brand innovation products, consumers' increasingly harsh eyes are also the reasons for Apple's continued decline in the domestic market."
IDC said the iPhone's high price specifically "led to the decline of Apple's domestic market," while the increased strength of Huawei's brand and its flagship phone's "excellent technology'" helped it continue to widen the gap over Apple. The latest iPhones start at $749 for the iPhone XR, and go all the up to $1,449 for the iPhone XS with the maximum storage option.