To connect your Android Wear powered wearables (e.g. smartwatches) with your Android phone you need a special Android Wear manager app installed on your phone. Android Wear manager app by Google bridges your phone with your wearables and lets you control voice action preferences, adjust notification settings, and configure devices.
For your information, Android Wear is a version of Android operating system that is designed for wearable devices such as smartwatches. LG G Watch, Samsung Gear Live, Moto 360, etc. are examples for Android Wear powered smartwatches and these devices will be available for the public shortly.
Android Wear app connects your phone to your smartwatch. Once you install and open the app, you will see the option to choose an available device. Once you are connected, you can do various things from the app like changing the agenda, setting an alarm, timer, etc.
Install Android Wear app from Play Store for free.