My listening English was not good before. I used to practice listening one-two hours a day, then I also read the text loudly. After 2 monthes, my listening was improved a lot. Also, you have to practice according to your current level, improve day by day. Good luck!

First u can listen to some clips and try your best to write down what u have heard as much as you can.

Then check the text, find out what words u didn't catch.

And practice it several times a week. u may make great progress on it.

My English listening is not good, too. 
I advise you that you should listen and speak English more. Speaking can increase English. Because you speak more English, you can remember the pronouciation of the vocabulary. When you are listening them, you can know the vocabulary quickly. 
Listening also can increase English. 'Practice makes perfect'. Listening more English vocabulary and sentence can get lots of experience. 
That is all. I hope my answer can help you learn English well. 

Everyone is born with the ability to learn, but whether or not you can do this well depends on your learning habits. Researching shows that successful learners have some good habits in common. Students show that if you're interested in something you bring is more active, and it is also easier for you to pay attention to it for a long time, good learners often connect with something interesting. So if you want to learn English or improve your English listening, then you can listening the English tapes. 

Without great patience, you will never be a great listener. - Luke Shen-Tien Chi

Listening, listening and listening.

A basic principle of improving your listening skill is to listen frequently. - Luke Shen-Tien Chi

Listen one sentence by one sentence. Write it down and listen again and again, until you can understand it easily. 

The key word: persistence.

Knowing exactly how the alphabet sounds and vowel sounds are  what many people lack in learning the English language. If you do not know how they sound you can never achieve fluency. If you do not know what to listen for, you will never learn it effectively.