When respondents were asked to give the most important reasons for choosing the train for their journey, the environment came in joint top position.
The survey was carried out last year and the conclusions were based on 1,234 onboard interviews.
In answer to the question "why did you choose to travel with SJ" some 36 percent said that they were thinking about the environment. That is a considerable increase since 2005 when 24 percent gave the environment as their main motivator.
A similar number said that they chose to take the train so that could relax.
Women were most worried about the environment, according to SJ. Among men, climate concerns were only fifth on their ranking of reasons.
"We're clearly seeing how travellers' environmental awareness is increasing, at the cost of both the car and plane," said Sven Andersson, head of SJ's customer and market analysis department.
Last year there were 37.4 million long distance passenger journeys by train, which accounts for 16 percent of all private journeys. Air travel accounts for 14 percent, while the car still dominates with around 66 percent of private journeys. 6 percent were by bus.