The molecular sieve SAPO-35 with different silicon content has been synthesized in a non-aqueous medium using haxamethyleneimine template. It has been characterized by XRD, SEM, Carbon and Nitrogen analysis, MASNMR, FT-IR techniques and Methanol to olefin reaction. The study indicates that XRD, FT-IR and Si-29 MASNMR properties did not change on increase in silicon incorporation. No silicon ilands were found on increase in silicon concentration. However, SEM photograph reveals that the particle size increased on increase in silicon content in the framework. The morphology also changes from bundles of platlets to cuboid, on more silicon incorporation. The catalytic activity of methanol to olefin conversion increases with silicon content and the selectivity is higher than ZSM-5 catalyst. Butene is formed as a main product.