BackgroundColorectal cancer takes the second place in the highly developed countries morbidity increases, for females it takes place after breast cancer, for males after lung cancer colorectal cancer occupies about 3-5% from the cancer of digestive tract. In the western Europe, united states of America it occuries 12.6% on males and 14% on females, for Pathological structure it occurs mostly in the proximal part and adenocarcinoma is diagnosed 95%. Colorectal carcinoma occurs more at the age of 20-40 but people aged 40-50 are mostly affected and males are affected more. Lately it has tendency of increasing amond the population 40-120 case on 100000 in a year approximately 5-10 people are affected newly. For our country by health statistical information colon cancer was 94 from it 49 occur on females, cancer of rectal and anus canal was 237, from it 99 occur on females, 37 case of colorectal cancer are registered newly in a year approximately, 19 occurs on females cancer of rectal and anus canal was 45 from them 16 are registered newly on females the number of patients with colorectal cancer has tendency of increasing. Among Mongolian population morbidity of colorectal cancer is increasing nowadays but any research has not been done to reveal pathology early and to diagnose. This became base of our research work.GoalAim of our study is to define peculiarity of colorectal cancer and its early pathology and to study some factor of aetiology connectea with cancer forming.Objectives:1. To define peculiarity of pathology of colorectal cancer.2. To diagnose early pathology of colorectal cancer by pathological method.3. To diagnose colorectal carcinoma by international histological classification and determine cell secretion degree.4. To define some genetic peculiarity of factors which affects to colorectal carcinoma.Novelty of research workNovelty of research work is to study colorectal carcinoma and its early pathology in combination with the method of endoscopy and molecular biology.Materials and MethodsIn the research 315 biopsy material of 142 patients with colorectal carcinoma of 2004-2008, 56 biopsy material of colorectal endoscopy of 2007-2008 are involved.1. Histological basic painting method.2. Method of molecular biology. We revealed affect of human papilloma virus infection in 39 surgical and endoscopyic material by using general GP5, GP6, MY11 primer in PSR.ResultsIn our study totally 198 people were involved from them (average age 45.8+ - 0.4), 46.0%(n=91)-male, 54% (n=107) female. If we see people involved in the study by age classification, 8 (5.9%) at the age of 20-29, 21 (10.3%) at the age of 30-39, 39 (19.3%) at the age of 40-49,45 (22.4%) at the age of 50-59, 56 (27.7%) at the age of 60-69, over 70-79 (14.3%). If we see colorectal carcinoma by anatomical location most location was in 45 (22.7%) in sigma, 52 (26.2%) in rectus. Seeing from endoscopic biopsy analyse pathology which involved whole colorectus occupied 10 (35.6%). By international histological classification of cancer which was adopted from WHO. In our study polyp occupies 21 (10.6%), adenoma 24(12.1%), adenocarcinoma 137 (69.2%), metastatic carcinoma 6 (3%), chronic inflammation or with change dysplasia 10 (5.1%). If we see endoscopic biopsy analyse it is 56 (28.3%) of people involved in the research. Hyper plastic polyp 21 (36.1%), adenoma 6 (25%), adenomatous polyp 8 (33.3%) occupces, Tubular adenoma polyp 7 (29.2%), villous adenoma 3 (12.5%) from carcinoma adenomatous carcinoma occupces 98 (71.5%), mucous carcinoma 7 (5.1%), carcinoma with flat cell 8 (5.8%), carcinoma with ring cell 5 (5.1%), carcinoma witout secretion 13 (9.5%), carcinoma with metastases 6 (4.3%), one of factors of etiology which affects to colorectal carcinoma is human papilloma virus. In the biopsy material of surgery and endoscope involved in the research it reveals negative in sensitive primer which reveals all the type of papilloma virus.Conclusions:1. Colorectal carcinoma occurs 19.3% at the age of 40-49, 22.4% at the age of 50-59, 27.7% at the age of 60-69, it has tendency of increasing rohen age becomes older. It occurs 14% over 70.2. By location of anatomy colorectal carcinoma it occupies 50-60% in sigma and rectus.3. Noncarcinomous polyp of colorectal carcinoma is situated in many parts of intestine carcinoma with many polyp occupies 35.6%of total carcinoma.4. By histological classification mostly carcinomous and noncarcinomous carcinoma of epithel and adenomous cell originated occupy.5. Papilloma virus hasn’t been releaved in the sample endoscopic sample.