Objective: Apolipoprotein (Apo) E- ε 4 is the first identified important susceptible gene of late-onset family and sporadic Alzheimer disease. Apo E E4 or ε 4 chained other genetic products probably play a certain actions in occurrence of Alzheimer disease, but their biological basis is unknown. To explain the relevant biological mechanism between ApoE and Alzheimer disease is still the key in next study. Data source: Computer Medline database is used to search the relevant papers from January 1978 to January 1999, with the words of "develop", "ApoE" and "Alzheimer", limited in English version. Simultaneously, the relevant papers are looked up from China Journal Database from January 1978 to December 2003, with the words of "ApoE, Alzheimer disease and development", limited in Chinese version. Study selection: Preliminary examination is done to the data. Inclusive criteria: relevant papers on ApoE gene and Alzheimer disease, including the study of both animal experiment and clinical basic research. Exclusive criteria: repeated study, summarized and Meta analysis papers. Data extraction: Totally 55 relevant papers are collected, of which, 20 papers are included and 33 papers are excluded due to repeated experiment and summarized papers. Data synthesis: Of 20 experiments, 16 experiments explain that ApoE E4 or ε 4 chained other genetic products probably play a certain actions in occurrence of Alzheimer disease and 4 researches propose that ApoE- ε 4 is the susceptible gene of Alzheimer disease. Conclusion: It is viewed in majority at present that ApoE genotype determination cannot substitute any clinical and imaging diagnostic method, which is probably only a kind of assistant diagnosis to improve the specialty in clinical diagnosis. Being the susceptible gene of Alzheimer disease, ApoE- ε 4 is the important discovery in its research no doubt, but, many relevant questions are still at experimental and hypothesis stages. In the future, the great consideration should be still drawn on ApoE genotype determination of Alzheimer disease.