1, liver function test must be fasting, fasting time is generally 8-12 hours, for the first time liver function test, especially so. 2, liver disease patients in the day before the blood test is best to prohibit alcohol, this is because the liver function test a number of content measurement value and diet has a certain relationship, such as drinking alcohol easy to make certain serum enzyme values rise, after eating fatty food can make the blood lipid increase, etc.. Therefore, patients with liver disease must pay attention to fasting when doing the test to ensure that they can make scientific diagnostic results. 3, liver function test the night before the best not to eat too greasy, too spicy food, such food can make the lipid test significantly increased, so need to be 10 hours before the blood test to prohibit the consumption of food containing fatty is better. The day before the test should eat some light food; best not to eat food rich in carotene, lutein, because it may make the serum is yellow, affecting the jaundice index measurement results. 4, liver function test before if you suffer from a cold, it is best to do the test 7 days after the cold is cured, because the cold may affect the liver function test results. 5, the night before the liver function test should not stay up late, forbidden to take drugs, because taking drugs may lead to an increase in transaminases, affecting the accuracy of the liver function test.