These days the number of immigrants in Korea is increasing. Korea is well known of the one kind of race. = Korean is one of the well-known races all over the world. There has been very few different people in Korea.= Before, only Koreans are in Korea But due to globalization, more and more people from other countries is coming to Korea. So we can see many foreigner in the street nowadays. = but due to globalization, more and more people from other countries are coming to Korea that's why we can meet a lot of foreigners in the streets nowadays.

I assume that the immigrants bring new trends into our society such as their clothes, meals, lifestyle and tradition. Of course it could go against our culture.
However if the local culture stays unchanged, I guess it wouldn't be developed. = However, if our local culture stayed fixed, I guess it wouldn't be developed. Taking others and embracing them could makes our culture developed. = Welcoming others and becoming open to the change could make our culture develop.
In this progress our tradition could be completely different, though. = In this progress, our tradition would become completely different.
So I don't think the local culture could be threatened by them. I would say that ours would reach cultural diversity. = Therefore, I don't think local culture should be threatened by the foreign one. I would say that it is just a part of cultural diversity.