If you don't understand something right away, don't give up. Keep listening. The speaker might say something later that will help you understand the main idea.
Listen for key words. Key words are stressed. They are louder, longer, and higher pitched than other words. These are the words that the speaker thinks are most important in a sentence. For example, notice the stress and intonation in this dialogue: A: I went to the store. B: Which store?
Think about the situation and ask yourself these questions: Who is speaking? What is the relationship between the speakers? What are they talking about? Where are they? How do they feel?
Pay attention to body language, gestures, and facial expressions. This may give you a better idea about what someone is saying.
Listen with a specific purpose in mind. Ask yourself what you are listening for. Are you listening for general understanding of the whole lecture or conversation? Or are you listening for specific information?
Think about the speaker's attitudes or feelings. Is the speaker certain, uncertain, angry, happy, serious, joking? The tone of voice can help you understand someone's feelings on a topic.
Check your understanding by asking the speaker questions. For example, use expressions like Could you repeat that? and I'm sorry, I didn't catch that when you want the speaker to repeat something.
Write down new words and phrases you hear. Don't worry about spelling. Then look the new words up in a dictionary or ask a native speaker to explain what they mean.
Notice how spoken English is sometimes different from written English. Many words and expressions, such as phrasal verbs and idioms, are more common in spoken than written English. (来源：英语杂志 http://www.EnglishCN.com)
Don't worry about hearing every word. Often, English words are linked together or shortened so you cannot hear every word clearly. For example, speakers often use contractions (can't instead of cannot) and reductions (wanna instead of want to). Try to focus on the most important words and you will understand the main idea.
Listen to how speakers' voices go up and down. This is called intonation. What kinds of questions are they asking you? What kinds of responses do they expect from you? Listening to the rise and fall of their voices can help you understand more clearly.
Listen for new thoughts. When speakers finish one thought and start a new one, their voices fall to a slightly lower pitch and they may pause between the two thoughts. Also, the words within one thought are often linked together and sound like one big long word.
Listen for organization words such as first, then, next, after that, and finally. These words can tell you that a speaker is explaining something in chronological order.
Listen to songs in English. Songs can help you get a better feeling for the rhythm of the language.
Use closed captioning when watching English-language TV and videotapes. First listen and read the dialogue at the same time, then listen again without reading.