目的：探讨国人对乳糖耐受性。方法：采用不同剂量乳糖进行氢呼气试验。对136名健康汉族成人分为3组，A，B，C组乳糖负荷量分别为25g，12.5g，6.25g。D组为从C组氢呼气试验阴性中再给予12.5g乳糖重复试验。结果：A，B，C，D组乳糖吸收不良发生率分别为85.0%，48.9%，2.0%和46.7%；乳糖不耐受率分别为54.3%，30.4%，2.0%和20.0%。A，B，C组乳糖吸收不良发生率及乳糖不耐受率均有极显著性差异(P<0.001)；B，D组间均无显著性差异(P>0.05)。结论：国人乳糖耐受量为6.25g，饮用牛奶每次以125ml为合理营养。

OBJECTIVE: To find out the tolerance to lactose of Chinese. METHODS: Hydrogen breathing test (HBT) was used in 136 healthy adults of the Han nationality with different quantity of lactose A, B, C. The different groups of subjects were given 25 g, 12.5 g, 6.25 g lactose respectively. The subjects of the C group taking lactose with HBT negative were given 12.5 g lactose again were included the in D group. RESULTS: The test showed that the incidence of malabsorption for lactose of the A, B, C, D groups was respectively 85.0%, 48.9%, 2% and 46.7%. The intolerance was 54.3%, 30.4%, 2.0% and 20.0% respectively. The incidence of malabsorption of and intolerance to lactose were significently different among the A, B and C groups (P<0.001). There was no significant difference between the B and D groups (P>0.05). CONCLUSION: The tolerance quantity of lactose for Chinese is 6.25 g. Taking 125 ml milk for each time is reasonable.