This is difficult because there are not set expressions that I can think of in English for this. Is there a set expression for this in your native language? You would just say 'he refused to look after his parents'. In Australia , many aged people go to care homes. This is quite normal though. If you want to put some kind of moral or value judgement on it you might say ungrateful, disloyal, heartless, selfish etc but these words can be used for many situations, not just for the parent-child relationship.

The only specific expression that comes to mind is "nonfilial". You have to remember that care for aging parents does not carry the same moral obligation in the West as it does in East Asia.

I don't know why some common terms have not been mentioned yet. The first word I thought of is 'neglect'. It is most often heard when parents do not properly care for children, but it can work both ways. (Serious 'child neglect' and 'elder neglect' are crimes under the law if actual physical injury results.) > "You're being neglectful of your parents!" > "His parents were good to him, but now he neglects them so badly." Another word is 'negligent', which is also used in a variety of contexts, including parent/child relationships ... > "It's sad to see negligent children who fail to care for their elderly parents." The word 'uncaring' may not carry as much weight as the two previous terms, but does cast a very negative light on a person's character ... > "When he does visit his dad, he just seems so uncaring and anxious to leave." To be 'derelict' in your duty to do something is another word that implies a serious failure to meet certain responsibilities. It is probably used more in formal, written contexts and less often in day-to-day spoken language, but you could say ... > "Her son was certainly derelict in his duty to the poor woman." There are other words that work along these same lines, but these four should get you started on a good tirade :)

Your answer 'He/She refuses to look after his/her old parents' is already perfectly fine. But if you wish, you can also change the context and say similar things: He/She has no sense of responsibility to take care of his/her old parents. He/She has no sense of responsibility towards his/her old parents. He/She lacks obligation to take care of his/her old parents. He/She doesn't want to take care of his/her old parents. He/She reject the idea to look after his/her parents. 你可以看看英语亚洲免费网上教学: www.englishasiaonline.net :)

Not to sure I understand the cultural context. How about - irresponsible, selfish, self-centred, uncaring, self-interested, ungrateful, immature, unreliable, bloody minded, obstinate, negligent, egotistical, greedy, avaricious, thankless, unthankful, unappreciative, mean, miserly, stingy, tight,...