Spatial optical solitons were studied in Kerr medium with transverse nonperiodic modulation by numerical method. The results of numerical simulation show that there are three kinds of spatial optical solitons. They are petronas soliton, basic soliton under the conditions of lower and higher power of light respectively, and bipolar soliton characterized by stable transmission. The stability analysis of the three kinds of spatial optical solitons based on the linear stability is carried out to obtain the stable spectrum in stable transmission, from which the transmission conditions are generalized for stable transmission of the three kinds of spatial optical solitons.