Common pool resources (CPRs) are safe-guards and foundation for rural livelihood especially for the developing nations like India. Cooperation is needed to conserve CPRs due to its very features. Community institutions sometimes face conflicts to conserve commons cost-effectively. But, conflicts may simultaneously help and hamper the local governance of commons. For empirical verification, we have conducted a primary survey on 419 users of canal water, community forest and tank water in 11 CPRs dependent villages from West Bengal, India. We observed positive relations between conflict and collective action in conservation of commons. This finding seems to be conflicting with the notion that, conflict undermines collective action and therewith the potential for sustainability. We examined and found that successful informal communities are more conflictive and at the same time cooperative than formal one. The occurrences of supply, demand and policy side conflicts and conflict resolution methods are also not significantly different between formal and informal institutions. Therefore, conflict and informal institution have some positive impact for the successful conservation. We suggest that authorities have to study the nature and types of conflicts before implementing rules and institutional arrangements thereafter. Keywords – collective action, institutions, commons, conflicts, conservation