Oscar De La Huerte answered
Whether a Korean girl will find a black guy attractive is probably down to her own personal taste, so there can't really be a definitive answer to this question.
It might be worth bearing in mind though, that girls are much less likely to meet black men in Korea because there simply aren't that many black guys living in the country. How this might affect a girl's opinion of them will vary, I guess.
Korean woman looking for a black man
For some Korean girls, black men may seem exotic and exciting and perhaps something of a novelty. This might be a good way of starting up a relationship, but ultimately whether your love lasts will eventually come down to whether or not you are a good match Novelty wears off, and it's what's under the skin that counts the most in the end.
Why Korean women might not date black men For other Korean girls, dating a black man, or a man of any other race for that matter, might seem slightly daunting.
Koreans may struggle to understand the complexities of a different culture, and if there is a language barrier involved then this may be a further setback to any blossoming relationship.
Also, Koreans are very, very family orientated and it is possible that the less-than-progressive views of older generations will have a negative impact on an inter-racial relationship.
Interaction between Korean women and black men
How a Korean woman views black men may come down to her previous experiences with black men. To put this is simpler terms, let me use this example: Many older Korean women have grown up with a negative perception of American men due to the poor behavior of some US soldiers stationed in Korea following the Korean war. So, it's likely to come down to each individual woman's perception of black men.
Another example of this would be how, in certain parts of Los Angeles, gang hostilities between the Asian community and the Black community have meant that a relationship between a Korean woman and a black man would be subject to social stigma, and perceived negatively.
However, if negative perceptions are not a factor, and the environment is right, then there is no reason why a relationship between a Korean girl and a black guy shouldn't work out. But if the girl does think she has reasons to be skeptical, then you'll probably have to work a lot harder to convince her to go on a date!