Resistivity of materials is a fundamental property of solids and is widely used to understand underlying physics as well as to engineer device applications. Conventional four-probe measurement is usually employed to exclude the contributions from the parasitic contact resistances. Here, we evaluate the in-plane resistive anisotropy in Ca2RuO4 crystals by using a rotational square four-point probe (4PP) method, which measures an angular dependence of the resistance to sensitively detect the resistive anisotropy of materials. A clear sinusoidal dependence of the resistance has been observed, confirming the resistive anisotropy in this system. Finally, the resistance data is fitted with a theoretical angle dependence equation to extract the resistive anisotropy. The observed results are found matching with the actual resistivity of the sample.