In Contemporary China， there are two theoretical approaches to the dynamic mechanisms of local rule of law practices. One is the theory of national strategy of trial-and-error. It explores the logics of emergence and construction of local rule of law practices from the perspective of the central authorities. The trial-and-error of local level is the basic strategy for the construction of rule of law in China. There are two fundamental types: authorized trial-and-error and confirmed trial-and-error. The dynamic mechanisms of former focus on that local rule of law is directly driven by central authorities， while the latter is indirectly. However， both are selective under the national strategy． The other is the theory of local competition. It studies the logics of emergence and construction of local rule of law practices. Local competition is the dynamism for the development of the local rule of law. As for the reasons why there are competitions in rule of law， one is that the central government is a special model for local governance， and the other is the inherent need of local governance. In fact， there are no internal conflicts between the national strategy theory and the local competition theory， and they are just two aspects of an organic whole which are deeply embedded in the relationship of central-local governments． There are three basic difficult problems in the local rule of law practices. The first is the problem of insufficient theories， because it struggles in the cracks of the holism of national rule of law.The second is the short of local characteristics because the aim of establishing local rule of law is just a response to central polices .The third is the problem of local protectionism. Rule of law may become the legitimate tool of local interests. Actually， the fundamental reason for all these problems is the deviation of the dynamic mechanism of local rule of law. National strategy encourages local competitions which shape the national strategy in turn， and the internal dynamism of local rule of law is the local competition under the national strategy. The local rule of law practices under the national strategy may be ways of seeking political protection， but whether it is local competition or national strategy， the construction of the rule of law would be a tool of local improvement and development， bringing the local rule of law practices into paradox: pushing on the local construction of rule of law with ways other than rule of law， and covering up the illegal nature with the deception of rule of law. As a consequence， the local construction of the rule of law would be formalism． In the future， the local construction of rule of law should be based on rule of law in relationship between central and local levels. China may still take the trial-and-error strategy， but the trial-and-error of local rule of law should be regular under law provisions. Meanwhile， the local competition of the rule of law should be guided to respond to the society and not the central policies， then to be the dynamism and construction logics of local rule of law.