The incidence risk of colorectal cancer （CRC） is increasing at 4.2% year by year in China. Most effective way to reduce the death rate of CRC patients is to diagnose in quite an early stage. QiaoKou District is a chemical industry Zone of Wuhan with a long history, which has few data of CRC epidemiology. The investigators design the primary CRC screening for this district by healthy questionnaire, Fecal Occult Blood Test(FOBT) and colonoscopy. HanYang Areo has been chosen as Control for its non-industry environment.The crowd would be screen biennially. The high risk group would be intervened, such as resection of polyps or other specific treatment. A follow-up registration database has been built for analysis the relationship between incidence or death rate to high risk factors, such as age, life environment, lifestyles, base diseases and family history of cancer.

This study will provide some epidemiology dates of CRC to the local Government, and assist the governor to built a more effective screening system of CRC.

For this study, you will be asked to complete a personal interview. During the interview, you will be asked questions about your demographics (age, sex, etc.), underlying diseases, lifestyle, family history of cancer, awareness of CRC. It should take around 30 minutes to complete the interview.

Residents in high risk group need to have some special tests, including FOBT and colonoscopy. Intestinal neoplasm will be suggested to biopsy or remove under colonoscopy for pathological examination. All tests are free. The interviews will be performed in Residential area and special tests will be done in the hospital during a regularly scheduled visit to Pu-Ai hospita.You may be contacted at home by phone so that researchers can collect information about any changes in your health status.

Inclusion Criteria:

1. Aged 40-74
2. Resident of Qiaokou Areo，and at least ten years living history in this district
3. Willing and able to provide written informed consent and authorization
4. Willing to a personal interview and have some special tests

Exclusion Criteria:

1. Under 43 or older than 74 years of age
2. History of colorectal cancer
3. Mental disorders

Coulp of this study from a chemical industry Zone of Wuhan with a long history,seriously polluted environment， which has few data of CRC epidemiology.

HanYang Areo has been choosen as Control for its non-industry environment