Try these steps: 1- click on Import project (Eclipse, ADT, ...)
2- Choose main directory of your Eclipse project
3- Keep the defaults. The first two options is for changing jar files into remote libraries (dependencies). It mean while building Android studio try to find library in local system or remote repositories. The last option is for showing only one folder as app after importing.
4- Then, you will see the summary of changes
5- Then, if you see Gradle project sync failed, you should go to project view (top left corner). Then, you should go to your project-> app and open build.gradle.
6- Then, you should change your compilesdkVersion and targetsdkVersion to your current version that you see in buildToolsVersion (mine is 23). For example, in my project I should change 17 to 23 in two places
7- If you see an error in your dependencies, you should change the version of it. For example, in my project I need to check which version of android support library I am using. So, I open the SDK manager and go to bottom to see the version. Then, I should replace my Android studio version with my current version and click try again from top right corner
I hope it helps.