This research aims to prove that scientific approach is better than the conventional to improve students  mathematical connections abilities. Methods  used i.e. qualitative design with control group pretes-postes. The population of the research are the students of 10^th grade in all vocational high school in Sukoharjo, Jawa Tengah, Indonesia. The sample are students of 10^th grade at SMK Pelayaran Pancasila .The instruments used in the form of a question of mathematical connections, ability test..The  results of  it that significance level α = 0.05  shows learning that  scientific approach is  better than conventional learning  mathematical connection