noun
home country; country of origin
Refers to the country where a person was born or originally comes from. Often used in formal contexts such as immigration forms or official documents.
出身国を記入してください。
Please fill in your country of origin.
彼の出身国はブラジルです。
His home country is Brazil.
母国 is a more emotional term for one's motherland or homeland, whereas 出身国 is a neutral, factual term for country of origin.
Compound of 出身 (shusshin, 'origin') and 国 (koku, 'country').