A new conservative gyrokinetic full-f Vlasov code is developed using a finite difference operator which conserves both the L1 and L2 norms. The growth of numerical oscillations is suppressed by conserving the L2 norm, and the code is numerically stable and robust in a long time simulation. In the slab ion temperature gradient driven (ITG) turbulence simulation, the energy conservation and the entropy balance relation are confirmed, and solutions are benchmarked against a conventional delta f particle-in-cell (PIC) code. The results show that the exact particle number conservation and the good energy conservation in the conservative Vlasov simulation are advantageous for a long time micro-turbulence simulation. In the comparison, physical and numerical effects of the nu(parallel to) nonlinearity are clarified for the Vlasov and PIC simulations. (C) 2007 Elsevier Inc. All rights reserved.