 My topic is temporal changes of CT findings in patients with COVID-19 pneumonia, a cross-sectional study in South India. Coming to the background, the professional consensus, guidelines and criteria have been established steadily to facilitate the diagnosis and treatment of COVID-19 pneumonia. We all know that RTPCR is gold standard for diagnosis and the chest CT scan is more sensitive than RTPCR. I did the materials and methods of this e-paper is we conducted the cross-sectional study. The study sample is 150 patients with RTPCR positive test attending the department of radiology at KVG Medical College, Surya, Dakshin, Canada. And the study duration is between from March 2021 to June 2021. We included the inclusion criteria is the patient with at least one positive RTPCR result for SARS-CoV-192 was obtained with oropharyngeal or nasopharyngeal swab. At least one HR CT scan done before or after admission. The exclusion criteria includes the patient with pre-existing lung diseases such as TB or interstitial lung diseases. We are not included in this study. The method of data collection, the patients were divided into two groups based on the chest CT reports depending on WHO guidance for clinical management. We divided into group one and group two. Group one will have clinically stable patient that is respiratory rate less than 30 and oxygen saturation greater than 90% and absence of sense of respiratory failure and also the ARDS for shock. In group two, we have clinically unstable patients that is respiratory rate greater than 30 beats per minute and oxygen saturation greater than 90% and the patient will have respiratory failure needing mechanical ventilation. And also we included the patient with the ARDS and shock. The CT scan was obtained with 5mm slice thickness and it is reconstituted into 1mm slice thickness and we observed the pulmonary changes whether it is unilateral versus bilateral and central versus peripheral. The results were obtained by the two experienced radiologists of five years experience and we also observed the lower distribution that is whether it is upper, middle, lingular or lower and multi-lober distribution and we gave score of maximum 25. Less than 5% included we give the score is 1 and 5 to 25% we give score 2 and 25 to 50% of involvement of the lung we give score 3 and 50 to 75% we give 4 and greater than 75% we will give 5 and we divided into right upper lobe, middle lobe, lower lobe and left upper lobe and left lower lobe we give the score up to the 25, up to 1 to 8 is considered as mild and greater than 9 to 15 is moderate and greater than 16 is severe and we also see the distribution that is predominantly subplural, central or diffuse involvement. Here we can see the multiple peripheral, subplural, lobular and peribronchal area of ground glass opacity in the background of interstitial and interlobular subplural.