I think you taking the high road and aim for the "gain this startup as a Chinese subsidiary" route is the win-win situation here. Of course, I can only read so

I think you taking the high road and aim for the "gain this startup as a Chinese subsidiary" route is the win-win situation here. Of course, I can only read so much from your description, and maybe some things don't apply in your case. Temper everything I say with your knowledge of your Chinese userbase (if any). I mean sure, it might look like an affront on the work you've put in your site, but in the end, you've also found another group doing what you're also doing, probably just as dedicated as you are. Depending on the mutual language skills (maybe even consider using a telephone interpreter service https://en.wikipedia.org/wiki/Telephone_interpreting https://en.wikipedia.org/wiki/Telephone_interpreting), you might be able to find common ground and work together towards a collaboration agreement or outright acquisition -- whatever it is, just make sure to have it in writing that your company came up with the concept and design. Win-win for both sides, and that contract is then legally binding. Even more, if you're in talks with a very large Chinese company, having Chinese collaborators might actually work in your favor. TL;DR: You might have more to gain by working on a collaboration deal first. Just never lose sight of the fact that, in the end, they were stealing.