The reasons for the low profit of foreign investment in China's service industry are as follows:

1. Fierce market competition: The competition in China's service industry market is fierce, especially in some basic service fields, such as finance, catering, tourism, etc., domestic enterprises are very mature, and foreign-funded enterprises need to face fierce competition when entering the market, which will have a certain impact on their profitability.

2. Regional and cultural differences: China's regional and cultural differences are great, so foreign-funded enterprises may need to spend more time and energy to adapt to the local market environment and cultural background, which will also have a certain impact on their profitability.

3. Policy and legal environment: The policy and legal environment of foreign investment in service industry in China is relatively complex, and foreign-funded enterprises need to abide by relevant laws and regulations in China, and they need to be approved and managed by multiple departments, which will increase the cost and risk of enterprises.

4. Cost and talent problem: The labor cost of China's service industry is relatively high. At the same time, in some fields, such as finance and medical care, the requirements for talents of foreign-funded enterprises are also high, which will increase the operating cost and management difficulty of enterprises.