Like Samsung, ZTE and Huawei began in Asia as cellphone-component makers, giving them a manufacturing edge against U.S. handset makers, like Apple.
For example, ZTE can make products six to 10 months faster than its competitors, Cheng said.
Both Chinese companies also have more flexibility in customizing their products.
As for Huawei, the company's 20 years of experience in the information-communications-technology industry give it advantages in developing a better 3G or LTE device that's affordable, Huawei spokeswoman Elizabeth Wu said in an email statement to CNBC.
The companies' next strategy is expanding their distribution channels and adding more phones to mainstream carriers AT&T, Verizon, Sprint and T-Mobile. Chinese-made phones from these carriers often sell under other names, limiting brand recognition.
(Read more: Cybersecurity questioned after UK Huawei deal)
To reach this next tier, Chinese brands will need to increase their quality, analysts said.
Recent U.S. releases show that Chinese brands are moving in that direction: This year, Huawei released its first Windows phone, and ZTE's new Nubia 5 features a 13-megapixel Konica-Minolta sapphire lens, which makes the device one the top handsets for photography, although critics say it falls short of DSLR claims.
(Read more: Apple slips on a ring of blue glass)
"ZTE is in the place where Apple doesn't want to touch. They're moving the quality up increasingly and coming into the competition," said Michael Morgan, senior analyst with ABI Research.
However, Chinese companies still face many challenges with brand recognition and adapting to the ways Americans purchase smartphones.
"It's definitely not a cakewalk," Wharton's Zhang said. "You can't come in and clear the market. I don't think Apple or Samsung will let you do that without a huge fight."
(Read more: Google launches new Nexus 5 smartphone)
—By Evelyn Cheng