This data set contains archival raw, partially processed, and ancillary/supporting radio science data acquired during the Mars Orbit Insertion (MOI) phase of the Mars Global Surveyor (MGS) mission. The radio observations were carried out using the MGS spacecraft and Earth-based receiving stations of the NASA Deep Space Network (DSN). The observations were designed to test the spacecraft radio system, the DSN ground system, and MGS operations procedures; to be used in generating high-resolution gravity field models of Mars; and for estimating density and structure of the Mars atmosphere. Of most interest are likely to be the Orbit Data File and Original Data Record files, in the ODF and ODR directories, respectively, which provided the raw input to gravity and atmospheric investigations. The MOI phase extended from September 1997 to March 1999. On orbits 203-266 and 343-571 (approximately April and June-September 1998, respectively) the spacecraft periapsis was especially low giving the highest per-orbit sensitivity to gravity anomalies during the entire mission. Data were organized in approximately chronological order and delivered on a set of 159 CD volumes at the rate of 2-3 CD's per week. Typical volume of a one-day ODF was 300-400 kB. Typical volume of an ODR was 5-10 MB, and there could be multiple ODR's per day depending on DSN schedules and observing geometry.