We have no communication for almost one year because of this long distance relationship. But I am trying to contact him through online but he doesn't reply. What would I do?

Hello Angela & welcome

You do not give us much information.

It would appear that you are in a relationship with someone but you do not see them very often because of the distance involved.

So let's have a closer look

How long have you known this person?
How long have you been - or supposedly been - a couple?
How much time have you spent with this person since you have known him(?) and since you have been an item?

How often do you keep in touch ~ by phone, e-mail, text, letters, Facebook, etc?

How serious is this relationship supposed to be?

What has he said to you about this relationship?

Has he ever replied to your messages?

How old are you both?

How far apart are you?

Are you originally from the same place?

Are there other 'challenges' ~ eg language, cultural, religious, differences?

This information might help us to better understand what is going on, but, to be honest, this does not sound very encouraging ~ a long-distance relationship, with no contact for a year

How do you feel about it?

get over him(: there is a reson hes your ex not in all cases is it you cant get back together with your ex but if hes ignoring y0u then move on(: