2MASS J, K-photometry was used to select red clump giants and determine distances and interstellar extinction. We analyzed color-magnitude diagrams constructed for 10 sky regions which are mostly located near the Galaxy plane. The application of maximum-likelihood procedure to determine parameters of observed J – K colour distribution of red clump giants resulted in the isolation of this type stars brighter then K = 11^m. Based on the reddening of extracted stars, K-band extinction was determined in the direction of the regions under investigation. The extinction and its variations with galactic longitude and latitude agree with the extinction based on the model by Arenou et al.