We are very pleased to invite you to participate in the 9th International Congress of the Working Group on Soils of Urban, Industrial, Traffic, Mining and Military Areas, SUITMA 9. SUITMA 9 will be held in Moscow, Russia on May 22-27 2017. The congress will be hosted by the Peoples’ Friendship University of Russia (RUDN University, www.rudn.ru). This year’s theme for the congress will be «Urbanization: a challenge and an opportunity for soil functions and ecosystem services» Urbanization is currently among the most important land-use change trends globally. According to FAO and UN predictions, more than 6 billion people are expected to live in cities by 2050. In response to these issues, policy agendas are focusing on achieving and maintaining optimally functioning and sustainable use of urban ecosystems, for present and future generations. Soils of Urban, Industrial, Traffic, Mining and Military Areas (SUITMAs) differ substantially from natural zonal counterparts in their physical, chemical and biological features, their performed functions, and supported services. SUITMA is a working group of the International Union of Soil Science (IUSS); a world leading scientific community dedicated to investigating urban and technogenic soils. The SUITMA working group joins urban soil experts from all over the world. SUITMA has organized international congresses every two years since 2001 to address different aspects of urban soil science. Eight fascinating congresses were organized in Europe, Africa, USA, Mexico and China. In 2017, SUITMA 9 will be held in Russia for the very first time and will be hosted by the RUDN University in Moscow city.