Historically speaking，Israel and Saudi were two hostile countries who saw each other as ememies. Nevertheless，there have been remarkable changes in Saudi-Israel relations since the beginning of the 21th century，evolving from secret contacts and cooperations in particular areas to frequent bilateral interactions and public cooperations in recent years. Their relationship has also been transformed from traditional enemies to some kind of “allies”. In recent years，Iranian nuclear issue and the aftermath of upheavals in the Middle East have accelerated the formation of de facto anti-Iran alliance in which Israel and Saudi share common interests. Saudi-Israel relations are thus improved step by step with the help of their common ally，the United States. As two influential countries in the Middle East，the change of Saudi-Israel relations not only has repercussions on the bilateral level but also affects the geopolitical situation in the whole area. However，there are still obstacles on the road to normalization of Saudi-Israel relations，such as the Palestine issue，the universal anti-Israel feelings among Muslims，and the uncertainty of US policy in the Middle East and the domestic stability of Saudi Arabia. Generally speaking，there are clear signs that Saudi-Israel relations will get better and better. Moreover，there are motivations and conditions for further improvement of Saudi-Israel relations. Nevertheless，difficulties lying ahead surpass achievements that have already been made. Israel and Saudi Arabia could strenghthen their alliance in the security area while neither of them will promote the normalization of their bilateral relations in a short period.