As a famous historical and cultural city in China, Xi 'an has many characteristic landscape restaurants, which are suitable for holding birthday parties. The following are some recommended landscape restaurants:

1. Datang Furong Garden: Located near the Big Wild Goose Pagoda, it is a large-scale garden scenic spot with the theme of Tang culture. There are many antique buildings and beautiful gardens here, where outdoor birthday parties can be held and wonderful performances can be enjoyed.

2. Qujiangchi: Located in the southern suburbs of Xi 'an, it is a royal garden with a long history. There are beautiful lakes and exquisite buildings here, where you can hold indoor or outdoor birthday parties and enjoy the lakes and mountains.

3. Xi' an City Wall: Xi' an City Wall is one of the most complete ancient city walls in China and one of the landmark attractions in Xi' an. There are some special restaurants on the city wall, where you can hold birthday parties and enjoy the beautiful scenery of the city.

4. Daming Palace Ruins Park: Daming Palace is the imperial palace in the Tang Dynasty, and now it has become a large-scale park scenic spot. There are many ancient buildings and beautiful gardens here, where you can hold indoor or outdoor birthday parties and learn about the history of the Tang Dynasty.

5. Xi 'an Bell Tower: Xi 'an Bell Tower is one of the landmark buildings in Xi 'an and the largest existing bell tower in China. There are some special restaurants near the bell tower, where you can hold birthday parties and enjoy the bustling scene of the city.