Lao Cai city, like most Vietnamese cities, did not escaped last decade dramatic construction and huge urban extensions. Such metamorphoses can be explained by Vietnam’s recent rapid economic growth and are emphasized by Lao Cai location on the Chinese border. Local officers justified urban transformation by their will to capture ongoing institutional opportunities and investments in the context of the Greater Mekong Subregion (GMS) policy. They also want to get the city ready to the border opening and to the Chinese “go west” policy. In 2010 however, transformations remained largely disconnected to the local economic reality: uneven and imbalanced commercial relations with China; poor FDI; oversized or unused city equipments, etc. And the city was still partially landlocked due to poor transportation infrastructures coming from Hanoi and to a still difficult border crossing, for trucks and goods in particular.This disconnection or gap between city planning and economic reality is analysed as a result of the long lasting decades of isolation and disputes which characterised the Vietnam‐Chinese relations. This communication emphasizes the role of the territorial representations resulting of contentious configurations. My hypothesis is that these representations impact on regional construction and transnational territorial construction in various, diffuse but significant manner. They are subjective but long lasting factors which vary according to the actors considered. In order to track down their impact, this communication varies both scales and actors perspectives. It focuses on the only institutional (political and administrative) actors considered as key actors (even not sufficient) of the regional construction regulatory and material framework conception and implementation. The communication starts at the local level by studying the Lao Cai case, considered both relatively to its location at the Chinese border and along the Kunming‐Haiphong corridor. It questions then what is observed at this level at national and international scales.< Réduire