I purchased it $24 but do i must hold or, sell it and buy another?
I also think if btc go to hell, than china money would be invested in Monero, because their money is black money.
what do you think?
Depends on what kind of "investor" you are. If you are after the quick buck then sell it now until your losses are not too high and buy something else what fits more to your plans. If you thinking in longer terms then hold it and buy more if the price plunges.
Chinese money isn't "black money". They sometimes need to bypass local financial regulations or limitations to get their money to international markets, but that happens once in a few years so that would be quite a "niche market".