Similar to Snapchat, the app lets users to send private videos, GIFs and images to each other which disappear after 72 hours.
The Chinese technology company is best known for creating apps such as Toutiao, the largest AI-powered content platform in China, and short video sharing service TikTok.
ByteDance launched Duoshan during a live-streamed event in Beijing on Tuesday.
“As Douyin’s user base has grown, we noticed that users not only share their videos on the platform but share them with close friends and families,” Zhang Nan, CEO of TikTok said at the launch event.
By launching Duoshan, ByteDance hopes to put pressure on entrenched social media services such as Tencent’s ubiquitous chat and payment app WeChat.
In October, ByteDance raised US$3bn in an investment round led by Softbank.
The Chinese firm is now valued at $75bn, surpassing Uber’s most recent valuation of $72bn and making it the world’s most valuable startup.